[Federal Register Volume 63, Number 210 (Friday, October 30, 1998)]
[Proposed Rules]
[Pages 58460-58521]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-28118]



[[Page 58459]]

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Part II





Department of Transportation





_______________________________________________________________________



Research and Special Programs Administration



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49 CFR Part 107, et al.



Hazardous Materials: Requirement for DOT Specification Cylinders; 
Proposed Rule

  Federal Register / Vol. 63, No. 210 / Friday, October 30, 1998 / 
Proposed Rules  

[[Page 58460]]



DEPARTMENT OF TRANSPORTATION

Research and Special Programs Administration

49 CFR Parts 107, 171, 172, 173, 177, 178, and 180

[Docket No. RSPA-98-3684(HM-220)]
RIN 2137-AA92


Hazardous Materials: Requirements for DOT Specification Cylinders

AGENCY: Research and Special Programs Administration (RSPA) DOT.

ACTION: Notice of proposed rulemaking (NPRM) and public meeting.

-----------------------------------------------------------------------

SUMMARY: RSPA proposes to amend certain requirements in the Hazardous 
Materials Regulations (HMR) to establish four new DOT cylinder 
specifications and to revise the requirements for maintenance, 
requalification, and repair of all DOT specification cylinders. In 
addition, RSPA proposes to: revise the requirements for approval of 
cylinder requalifiers, independent inspection agencies, and nondomestic 
chemical analysis and tests; revise the cylinder requalification, 
maintenance and repair requirements; and to revise the requirements for 
hazardous materials that are authorized to be offered for 
transportation in cylinders. Finally, this NPRM incorporates a proposal 
to remove from use aluminum alloy 6351-T6 that was published in an 
advance notice under Docket HM-176A and terminates that docket (RIN: 
2131-AB51).
    This action is being taken to--simplify the HMR for construction of 
cylinders; provide for flexibility in the design, construction and use 
of cylinders; recognize recent advances in cylinder manufacturing and 
requalification technologies; promote safety though simplification of 
the regulations; reduce the need for exemptions; and facilitate 
international commerce. The intended effect of this action is to 
enhance the safe transportation of hazardous materials in cylinders.

DATES: Comment Date: Comments must be received on or before January 28, 
1999.
    Public Meeting Date: A public meeting will be held on December 8, 
1998; from 9:30 am to 4:00 pm. An additional meeting may be scheduled 
if there is substantial interest.

ADDRESSES: Written Comments: Address comments to the Dockets Management 
System, U.S. Department of Transportation, PL 401, 400 Seventh St., SW, 
Washington, DC 20590-0001. Comments should identify the docket number, 
RSPA 98-3684(HM-220), and should be submitted in two copies. Persons 
wishing to receive confirmation of receipt of their comments should 
include a self-addressed stamped postcard. The Dockets Management 
System is located on the Plaza Level of the Nassif Building, at the 
above address.
    Public dockets may be reviewed between the hours of 10:00 a.m. to 
5:00 p.m., Monday thru Friday, excluding Federal holidays. In addition, 
comments can be reviewed by accessing the DOT Homepage (http://
www.dot.gov). Comments may also be submitted by E-mail to 
``[email protected]''. In every case, the comment should refer to the 
Docket number set forth above.
    Public Meeting: The public meeting will be held in Room 3200-3204 
at the U.S. Department of Transportation's Nassif Building, 400 7th 
Street SW, Washington DC, 20590.

FOR FURTHER INFORMATION CONTACT: Cheryl Freeman, telephone number (202) 
366-4545, Office of Hazardous Materials Technology, or Ryan Posten, 
telephone number (202) 366-8553, Office of Hazardous Materials 
Standards, Research and Special Programs Administration, U.S. 
Department of Transportation, Washington, DC 20590-0001.
SUPPLEMENTARY INFORMATION:

I. Background

    Federal hazardous material transportation law (Federal hazmat law), 
49 U.S.C. 5101-5127, authorizes the Secretary of Transportation to 
regulate the manufacture and continuing qualification of packagings 
used to transport hazardous materials in commerce, or packagings 
certified under Federal hazmat law for the transportation of hazardous 
materials in commerce. The HMR, 49 CFR parts 171-180, contain 
requirements for the manufacture, use, and requalification of cylinders 
subject to Federal hazmat law, including defining materials and methods 
of construction, the frequency and manner of inspection and testing, 
standards for cylinder rejection and condemnation, cylinder marking and 
recordkeeping, authorizations for packaging hazardous materials in 
cylinders, filling, loading, unloading, and carriage in transportation.
    Historically, Federal authority to regulate the transportation of 
compressed gases was given to the former Interstate Commerce Commission 
(ICC) through the Transportation of Explosives Act, 35 Stat. 1135, 
section 233 (March 4, 1909), which was later amended in 1921, at 41 
Stat. 1445, Sec. 233. In 1911 the ICC adopted a series of ``Shipping 
Container Specifications,'' among which the ICC 3 specification for 
seamless steel cylinders was codified. That same year, the ICC 4 
specification for a lap-welded cylinder for anhydrous ammonia was also 
published. As the welding process improved, from the riveted/brazed 
welds to resistance welding and then butt welding by the metal-arc 
process, the ICC 4 Specification series was expanded to include the 
4BA, the 4BW, and others. By 1914, two other cylinder specifications 
were codified: the ICC 7 specification for steel cylinders for low 
pressure, nonliquefied gas, (which have carried over to the present 
regulations, but not as specification 7) and the ICC 8 specification 
for acetylene gas cylinders, which still exists today with minor 
changes.
    In 1930, the ICC implemented regulations for periodic inspection 
and testing of cylinders; the regulations, as amended, were first 
published in the Federal Register on December 12, 1940 (5 FR 4908). 
During the 1930's and 1940's, the Compressed Gas Association (CGA) 
developed and refined the water jacket test method for determining the 
serviceability of a cylinder. During World War II, there was a shortage 
of high pressure gas cylinders. Because of CGA's work on steel wall 
stress limitations, the ICC granted ``temporary'' regulatory relief to 
increase the gas carrying capacity of existing cylinders by allowing 
the cylinders to be filled 10% over their marked service pressures, and 
by marking those cylinders with a plus, ``+'', mark. Ten years later, 
the regulations were codified into the Code of Federal Regulations (15 
FR 8261; Dec. 2, 1950). In 1967, pursuant to the Department of 
Transportation Act, Pub. L. 89-670, 80 Stat. 931, regulatory 
responsibility for the transportation of dangerous articles in commerce 
was transferred from the ICC to DOT.
    Through rulemaking and the issuance of exemptions from the 
regulations under 49 CFR part 107, subpart B, materials other than 
steel (e.g., aluminum and composite cylinders) now are authorized for 
use. Nevertheless, apart from the substitution of the ``DOT'' 
identifier for the ``ICC'' identifier, many of today's basic 
requirements remain virtually unchanged from the time they were first 
incorporated into the regulations.
    Over the years, RSPA has received numerous petitions for rulemaking 
requesting various changes to the cylinder requirements. CGA filed most 
of these petitions that request changes to

[[Page 58461]]

the cylinder specifications. In 1969, CGA submitted a petition (P-69) 
containing six new proposals and revising eight previously-filed 
petitions. Many of these 14 petitions were handled in subsequent 
rulemakings such as Docket HM-69 adding a DOT 39 non-reusable, non-
refillable specification cylinder (August 24, 1971; 36 FR 16579), 
Docket HM-85 updating the DOT-4L cylinder material properties (Nov. 5, 
1971; 36 FR 21287), and Docket HM-99 adding the DOT-3T specification 
cylinder (Aug. 15, 1973; 38 FR 21989).
    In 1981, RSPA adopted a DOT 3AL specification under Docket HM-176 
(46 FR 62452). This new specification for a seamless aluminum cylinder, 
made of definitely prescribed alloys, was based in part on the 
petitions received from industry and an agency initiative to 
consolidate and eliminate the need for seven exemptions authorizing the 
manufacture of seamless aluminum cylinders. In 1984, CGA petitioned (P-
953) to include a welded stainless steel cylinder similar to the DOT-
4BW. At that time, CGA proposed the designation ``4SS'' for the new 
stainless steel cylinder.
    In 1990, CGA petitioned to add a new 3F specification for a 
seamless steel compressed gas cylinder designed for a high stress level 
similar to the DOT-3T, but with a stronger structural integrity similar 
to the DOT-3AA cylinder. The proposed 3FM specification provides for a 
greater efficiency in gas transportation.
    The above-mentioned petitions were given full consideration in the 
development of this NPRM. In developing this NPRM, RSPA worked closely 
with the cylinder manufacturing and maintenance industries, and held 
several meetings with CGA to obtain clarification of the CGA petitions. 
RSPA also held public outreach meetings with industry that were 
announced in the Federal Register. The industry proposals and petitions 
have been refined by RSPA based on RSPA's compliance inspections and 
exemption program, interpretations issued by RSPA, and certain industry 
consensus standards and practices that have proven to be safe. RSPA 
believes the proposals in this NPRM are consistent with sound industry 
practice and incorporate modern manufacture and requalification 
technology.
    Some of the more significant proposals contained in this NPRM are:
    1. The establishment of four new cylinder specifications that are 
more performance-oriented and the removal of several obsolete 
specifications. These proposed specifications are expressed in metric 
units, require marking of the cylinder with test pressure in place of 
service pressure, and are distinguishable by their specification 
designation markings.
    2. The new specifications allows greater flexibility in the design 
and construction of metric-marked cylinders.
    3. Independent inspection of all metric-marked cylinders, both 
seamless and welded.
    4. Design qualification testing of metric-marked cylinders.
    5. The requalification of metric-marked cylinders and certain 
nonmetric-marked cylinders using thickness and shear wave ultrasonic 
testing in place of the volumetric pressure test.
    6. Requiring any person who performs a requalification function 
that requires marking an inspection or retest date on the cylinder to 
have approval from the Associate Administrator for Hazardous Materials 
Safety (herein after referred to as the Associate Administrator).
    7. Standardizing the requirements for the repair and rebuilding of 
DOT 4 series cylinders, other than the DOT 4L.
    8. Allowing a 10-year interval for requalification of DOT 3-series 
metric-marked cylinders used in certain types of service.
    9. Allowing a 15-year interval for requalification of certain DOT 
4-series metric-marked cylinders used in certain types of service.
    10. Allowing, upon approval by the Associate Administrator, the 
application of requalification markings on cylinders by using 
alternative methods that produce durable legible marks.
    11. Implementing valve damage protection and puncture resistance 
criteria for all DOT specification cylinders used for Division 2.3 or 
6.1 materials in Hazard Zone B, and puncture resistance criteria for 
those in Hazard Zone A.
    12. Discontinuing authorization for a filled cylinder with a 
specified service life from being offered for transportation in 
commerce after its service life has expired.
    13. Providing filling pressures for metric-marked cylinders based 
on critical temperature, test pressure, and draft ISO Standard 11622.
    14. Requiring that pressure relief devices on all metric-marked 
specification cylinders be set at no less than test pressure. Requiring 
that pressure relief devices on all 3-series, nonmetric-marked 
specification cylinders be set at no less than test pressure from the 
first requalification due after the effective date of the final rule.

II. New specification Standards for Metric-marked Cylinders

A. Consolidation of Cylinder Standards

    As discussed above, the current cylinder requirements have their 
origin in the early 1900's. The regulations were developed in a 
piecemeal fashion, with adjustments being made to address particular 
situations and problems on a case-by-case basis. This NPRM represents 
RSPA's first comprehensive review of the cylinder requirements.
    RSPA proposes to establish four new cylinder specifications for 
seamless and welded cylinders. These proposed cylinder specifications 
are more performance oriented and incorporate provisions that recognize 
certain domestic and international practices. Cylinders made to these 
specifications would be marked in metric units and would be 
distinguished by a unique specification marking that closely 
approximates the markings in draft International Standards Organization 
(ISO) and the European Committee for Standardization (CEN), Technical 
Committee, entitled ISO/TC58/SC4 ``Gas Cylinders Operational 
Requirements,'' based on CEN Standard EN 1089-1, ``Transportable gas 
cylinders--Gas cylinder identification--Part 1: Stampmarking.''
    The new seamless cylinder specifications are identified as DOT 3M, 
3ALM, and 3FM. The welded cylinder specification is identified as the 
DOT 4M. Eventually, RSPA anticipates that the DOT 3M specification will 
replace the current DOT 3A, 3AA, 3AX, 3AAX, 3B, and 3BN specifications. 
The DOT 3ALM specification will replace the 3AL specifications. The DOT 
3FM will replace the higher strength 3AA and the 3T specifications. The 
DOT 4M will replace the 4B, 4BA, 4BW, 4B240X, 4B240ET, and 4E. In 
future rulemakings, RSPA plans to propose new metric-marked cylinder 
specifications to replace the current specifications for the DOT 3E, 
3HT, 4D, 4DA and 4DS; the 4L; the 8 and 8AL; and the DOT 39.
    The basic specification requirements, those common to most metric-
marked cylinders, are in proposed Sec. 178.69. This section contains 
definitions, material of construction, duties of the inspector, and 
criteria for all design and production qualification tests that may be 
required by the individual specifications. Proposed Sec. 178.70 
contains requirements applicable to seamless cylinders. The individual 
specifications, containing additional requirements, are in Sec. 178.71 
for the DOT 3M, Sec. 178.72 for the DOT 3ALM, and Sec. 178.73 for the 
DOT 3FM. Proposed Sec. 178.81 contains

[[Page 58462]]

requirements applicable to DOT 4M welded cylinders.
    In all cases where the new proposed specifications differ, the new 
specification requirements will have a level of integrity that is 
equivalent to, or greater than, the current nonmetric specification 
requirements. Significant changes from current requirements are 
discussed further in this preamble.

B. Cylinder Filling Limits

    CGA petitioned RSPA to change the test pressure from 5/3 times 
service pressure for currently authorized DOT specification seamless 
cylinders to 3/2 times service pressure for newly constructed DOT 
specification seamless cylinders. In effect, the CGA proposal would 
increase the filling limit for most of the new seamless DOT 
specification cylinders to that currently authorized for cylinders 
marked with a ``+'' sign (see 49 CFR 173.302(c)). In the historical and 
technical information provided to support its petition, CGA stated:

I. Background

    In 1942 during the height of industrial production for WWII, a 
shortage of high pressure gas cylinders developed. The shortage was 
hampering the War effort. The three manufacturers of large size 
cylinders were also forging shells and bombs and did not have 
capacity to forge those and the required quantities of high pressure 
steel cylinders.
    The War Production Board brought this concern to the Compressed 
Gas Association (CGA) to seek a remedy for the shortage of high 
pressure cylinders. One idea was to start up new production by 
spinning seamless tubing, which was initiated by Cueno-Press and 
Taylor Forge; but that would take months. An immediate ``temporary'' 
relief was conceived which was to increase gas carrying capacity by 
allowing an ``overfill'' of existing cylinders. After careful study, 
the increase of 10% in filling pressure (i.e., from 2015 to 2215 
psi) was considered safe and technically sound because of the 
conservative design required by DOT Specification 3A and of the 
existing high pressure cylinders produced thereto.
    For example: A 10% increase in wall stress at the increased 
filling pressure maintained the operating stress well below the 
yield point of the steel; and so, cyclic fatigue failure would not 
become a factor for the ductile, low strength steel. Furthermore, 
the operating stress would still be far below the ultimate tensile 
strength providing an adequate safety factor which related service 
pressure to rupture pressure; and the only way the cylinder pressure 
of permanent gases could reach burst pressure was by involvement in 
a fire.
    By joint agreement between the War Production Board, Interstate 
Commerce Commission (ICC) and the Gas Industry, it was decided to 
immediately allow a ``10% overfill'' for the existing cylinder 
fleet. This was to be allowed for both flammable and non-flammable 
permanent gases.
    To make this effective required a change in the ``Regulations'' 
covering ``Charging of Cylinders with Non-liquefied Compressed 
Gases'' because it was to be applied to existing cylinders as well 
as new production. Therefore, section 173.302 was changed and 178 
was not changed to cover cylinder design and production. Thus, a 10% 
increase in the gas carrying capacity of the existing cylinder fleet 
and new current production was immediately achieved. This had the 
effect of adding 10% additional cylinders.

II. Technical Rationale for Allowing 10% Higher Fill Pressures

A. Introduction

    The fleet of DOT 3 Series cylinders in use during the war years 
performed safely without a service failure, notably from fatigue or 
gas pressure rupture. Thus, the carefully considered decision to 
allow the charging pressure to be increased by 10% was considered to 
be proven safe and technically valid.
    The compressed gas industry monitored performance of their 
cylinder fleets and concluded that the ``temporary'' over-filling 
procedure could safely become a permanent regulation. However, CGA 
decided to recommend certain controls to justify permanent 
continuation of this change which effected the design safety factor. 
Those controls are now contained in CFR Title 49, clause 173.302 (c) 
entitled ``Special filling limits for Specification 3A, 3AA, 3AX, 
3AAX and 3T cylinders''.
    The technical rationale for those controls was: * * *
    (1) ``That such cylinders are equipped with frangible disc 
safety relief devices (without fusible metal backing) having a 
bursting pressure not exceeding the minimum prescribed test 
pressure.''
    Rationale: This was to guarantee that cylinder pressure from any 
source could never reach the cylinder design burst pressure. 
Therefore, lowering the ratio of service pressure to rupture 
pressure, was meaningless because the cylinders would be equipped 
with a ``rupture port'' which would vent the gas pressure at a pre-
determined pressure and prevent the cylinder from ever reaching its 
``burst'' pressure. * * *
    (2) ``That the elastic expansion shall have been determined at 
the time of the last test or retest by the water jacket method.''
    Rationale: In the 1930s and 1940s the CGA had developed and 
refined the water jacket test method, and developed the mathematical 
relationship of wall stresses as measured by the elastic expansion 
of individual cylinder designs. The average wall stress as 
determined by elastic expansion measured by the water jacket 
hydrostatic test was limited to a specified stress less than the 
permitted maximum design stress. For example, 3AA design cylinders 
were to be rejected if the elastic expansion exceeded a value 
equivalent to the strain developed at an average wall stress of 
67,000 psi; whereas, the design wall stress limit in 178.37-10(b) is 
70,000 psi. This 4% decrease in wall stress was selected because 
elastic expansion measures the average effective wall thickness and 
not the minimum. At the same time it was concluded that a small 
increase (i.e., 4%) in the stress at isolated areas of a cylinder 
could be safely tolerated to allow for localized damage or thinning; 
and a ``Maximum wall stress limitation'' was set; e.g., 73,000 psi 
for 3AA design cylinders. This procedure of elastic expansion 
control was developed to further justify the permanent use of the 
``10% overfill'' by guaranteeing that such cylinders would be 
controlled by limiting the loss of wall thickness so that the stress 
at service pressure would be below the yield point of the cylinder 
steel. * * *
    (3) ``That either the average wall stress or the maximum wall 
stress shall not exceed the wall stress limitations shown in the 
following table.''
    Rationale: Wall stress limitations for both average wall and 
isolated spots were developed for each ``class of steel'' used for 
ICC 3, DOT 3A, and DOT 3AA cylinder designs. (Much later DOT-3T was 
added.) These limits were selected from known physical properties of 
these steel classes; and were set to assure that stress at operation 
pressures were: (1) well below yield point and (2) that an adequate 
burst pressure to service pressure ratio was obtained. This clause 
amplifies the preceding clause 2.
    (4) ``That an external and internal visual examination made the 
time of test or retest shows the cylinder to be free from excessive 
corrosion, pitting, or dangerous defects.''
    Rationale: The body of data and service experience available 
within the CGA had proven that the design criterion for DOT high 
pressure cylinders was eminently safe; especially as regards cycle 
life and rupture in service. The only cause of cyclic or tensile 
rupture would be damage inflicted during manufacture or service. 
Thus, the visual inspection before and during use was considered to 
be an essential safety measure, which continues to be true today.
    (5) ``That a plus sign (+) be added following the test date 
marking on the cylinder to indicate compliance with paragraphs (c) 
(2), (3) and (4) of this section.''
    Rationale: This was to force both the cylinder manufacturer and 
user to take a physical act to signify their guarantee of compliance 
with the control methods. This also was an easily discerned mark 
that permitted personnel to identify which cylinders were 
satisfactory, safe and qualified for charging to the ``10% 
overfill''.

B. Wall Stress and Safety Factors of Series 3 DOT Cylinders

    The most common high pressure cylinder in use in 1942 was the 
ICC-3A-2015 with size of 9'' O.D. x 51'' long, rated at 220 cubic 
feet oxygen capacity. This cylinder made of normalized intermediate 
manganese steel had an ultimate tensile strength of about 95,000 psi 
and had excellent ductility and good charpy impact strength at 
-50 deg.F. to assure safe fracture performance. The design stress at 
test pressure was 49,500 psi which with the 5/3 test pressure ratio 
allows a stress of 29,600 psi at 2015 psi service pressure. The 
yield point was about 69,000 psi (about 0.73 x U.T.S.). Thus the 
service stress was about 50% of yield stress, which level assured a 
long (virtually infinite) cycle life. The burst stress to service 
stress ratio (safety factor) was about 3.2 (95,000  
29,600).* * *

[[Page 58463]]

    This ratio of operating stress compared to ultimate strength was 
obviously a conservative design. The conservatism is more obvious in 
view of the fact that the cylinders were seamless, forged, high 
quality steel pressure vessels which have no stress concentration 
points in the longitudinal plane of major stress. Furthermore, they 
were used in non-corrosive gas service and have no source to 
increase the contained pressure during use except by the small 
fluctuations in ambient temperature or a fire. The cylinders are 
also subjected to periodic requalification. In view of these facts/
data and the excellent service record, the decision was made in 1942 
to allow stress to increase about 32,600 psi at service pressure for 
the ``10% overfill''. This equates to a working stress to burst 
strength ratio of 2.9 (95,000  32,600).
    Thus the ``10% overfill'' was considered technically appropriate 
and eminently safe as a way to increase the oxygen carrying capacity 
from 220 CF to 244 CF. These cylinders have continued in service for 
over 50 years with a perfect safety record as regards cyclic or 
pressure rupture in service. The same effective stress at test 
pressure can be achieved by testing either at 5/3 of 2015 or 3/2 of 
2215. These pressures are 3358 and 3323 which stresses the wall to 
49,350 and 48,720 psi respectively. This 1.2% difference in test 
pressure stress would be inconsequential with respect to cylinder 
safety. Therefore, the test pressure in the DOT 3A, 3AA, and 3T 
specifications can safely be changed to 3/2 instead of 5/3 service 
pressure. The following paragraph describes graphic presentation of 
the situation with intermediate manganese normalized and chrome-moly 
quenched and tempered, which represents virtually 100% of the 3A and 
3AA cylinders in the U.S.         * * *
    It is proposed to write all the ``10% overfill'' into the design 
conditions for DOT 3A, 3AX, 3AA, 3AAX, 3F (new) and 3T. This can be 
accomplished by merely changing the required test pressure from 5/3 
x service pressure to 3/2 x service pressure. For all intents and 
purposes, the cylinders would be exactly the same as discussed 
above. * * *

III. Conclusions

    1. DOT 3A and 3AA cylinders have been in use since 1942 (54 
years) with a ratio of test pressure to service pressure of 3/2. At 
time of manufacture or retest, the cylinders are tested at 5/3 x 
service pressure; but the service pressure is increased by 10% for 
filling.
    2. The 10% overfill pressure times 3/2 results in a wall stress 
at test pressure only 1% less than the requirement to test at 5/3 
times marked service pressure.
    3. The 3/2 test pressure would result in a calculated minimum 
wall of barely 0.001 inch less for a current cylinder with a 0.250 
wall minimum.
    4. The tiny decrease in wall thickness and effect of 1% lower 
stress at test pressure would have no effect in overall cylinder 
safety.
    5. The service record since 1942 (54 years) has been perfect as 
regards rupture under gas pressure and cyclic fatigue 
characteristic. The change to 3/2 test versus 5/3 does not change 
any measurable characteristic which would effect these failure 
modes.
    6. The ASME Code uses a 3/2 test pressure to working pressure 
ratio.
    7. Europe (18 countries) uses the 3/2 test to service pressure 
ratio.

IV. Recommendation

    The minimum prescribed test pressure shall be 3/2 times the 
marked service pressure for all cylinders with a marked service of 
500 psi or greater for all Series 3 steel cylinders. This should 
also be considered for cylinders made of nickel, aluminum or 
stainless steel.

    In considering the issue of cylinder filling limits, RSPA also 
reviewed technical information supplied by cylinder manufacturers and 
by holders of exemptions that authorize either a test pressure of 3/2 
times service pressure or 10% overfill for materials not currently 
specified in 49 CFR 173.302(c), the hazardous materials information 
system data base for incidents involving ``+'' marked cylinders, and 
the work currently being done by the ISO and the United Nations Group 
of Experts on the Transport of Dangerous Goods. After reviewing all the 
available information, RSPA has concluded that from a transportation 
safety perspective, there is no technical reason or safety experience 
which would prohibit increasing the cylinder filling limits for 
seamless cylinders to those comparable to the levels currently 
authorized in 49 CFR 173.302(c). Therefore, RSPA has accepted the CGA 
proposal to increase the filling limits for new cylinders, in 
principle, but has chosen to limit the proposal for increased filling 
limits to metric-marked DOT Specification cylinders. Additionally, RSPA 
has not changed the requirements in 49 CFR 173.302(c) for the current 
DOT specification cylinders, but has moved them to proposed 
Sec. 173.302a(b).
    With regards to existing cylinders, RSPA is considering a process 
for accepting certain DOT specification cylinders as meeting the new 
metric specifications, but is still considering various conversion 
criteria. RSPA solicits comments from interested persons as to the 
interest and feasibility of developing such a conversion program and, 
if feasible, specific criteria for requalifying and conversion of 
existing cylinders.

C. Specification Markings on Metric-marked Cylinders

    In the CGA submission to RSPA, it was requested that cylinders be 
marked in bar rather than psig. Bar is an internationally accepted 
metric unit for pressure in the compressed gas industry. This change 
would help make marking DOT specification cylinders consistent with the 
practice in most European countries which are currently marking 
cylinders with the test pressure shown in bar.
    While considering this request, RSPA reviewed its current marking 
requirements as well as two draft documents on the subject of cylinder 
marking being considered by the ISO and the CEN. The documents are ISO/
DIS 13769, ``Gas cylinders--Stamp marking,'' and CEN Standard EN 1089-
1, ``Transportable gas cylinders--Gas cylinder identification--Part 1: 
Stampmarking.''
    Based upon this review, RSPA proposes to change the way DOT 
specification cylinders are marked. The new marking scheme will change 
the number and sequence of marks required to be placed on DOT 
specification cylinders by manufacturers and is consistent with the 
sequence being proposed by both ISO and CEN. However, RSPA does not 
proposed to require all of the cylinder marks contained in either the 
ISO or CEN documents. The proposed marking scheme will also make it 
easier to identify those cylinders manufactured to the proposed 
specifications. Additionally, the marking scheme is similar to the type 
of marking scheme contained in the United Nations Recommendations for 
the Transport of Dangerous Good for non-bulk packagings and 
intermediate bulk containers.
    The proposed marking sequence, with each element separated by a 
slash mark, is as follows:

DOT Specification
Country of origin
Manufacturer's identification
Serial number
Stamp for non-destructive testing (if applicable)
Minimum wall thickness
Water capacity (liters)
Test pressure (bar)
Identification of alloy
Tare weight (kg)
Identification of inspection agency
Test date
REE (if applicable)

    The most significant change is the marking of the new specification 
cylinders with test pressure instead of service pressure. DOT 
specification cylinders have always been designed to test pressure 
rather than service pressure. Specifically, the stress formulas used to 
determine the minimum wall thickness of DOT specification cylinders are 
calculated at the minimum test pressure.

[[Page 58464]]

Additionally, as currently authorized in 49 CFR 173.302(c), many 
cylinders used to transport compressed gases which are not liquefied, 
dissolved, toxic or flammable are filled to a pressure 10% in excess of 
their marked service pressure and 49 CFR 173.304(f) specifies, with 
limited exceptions, that the pressure in the container at 130 deg.F 
shall not exceed 5/4 times the marked service pressure. While marking 
the test pressure rather than the service pressure will require the 
training of persons who fill cylinders, it should not have any adverse 
safety effects since inadvertently filling a cylinder to the marked 
test pressure, in bar, would result in the cylinder being filled to a 
lower pressure than the currently marked service pressure in psig. 
Further, most cylinders are filled by a person who uses a filling table 
that shows the values already adjusted for changes in temperature and 
elevation. RSPA envisions that cylinders marked with test pressure will 
also be filled by using filling tables.

III. Independent Inspection--New DOT Specification Cylinders

    A DOT specification cylinder is, and has been for the past sixty 
years, a widely recognized standard for the safe transportation of 
compressed gases. This wide acceptance has resulted in significant 
economic benefit to domestic industry far beyond the value of the 
cylinders sold internationally. Market demand for gases and equipment 
has increased as a direct result of the reputation of the DOT cylinder 
for strength, durability and quality.
    Since the early 1900's, cylinders manufactured under DOT's ``high 
pressure'' specifications have required independent inspection, 
originally referred to as ``disinterested inspection.'' Occasionally, 
RSPA receives complaints from companies about costs of independent 
inspection or claims that the companies' employees are as knowledgeable 
and qualified, if not more so, as the independent inspector. However, 
RSPA's Office of Hazardous Materials Enforcement, through its 
compliance inspection program, has found a higher level of compliance 
with the regulations when inspection and certification functions are 
carried out by an Independent Inspection Agency (IIA) instead of by an 
employee of the manufacturing company. In order for DOT specification 
cylinders to be acceptable for service in most foreign countries, 
cylinders must be certified through an inspection process which is not 
controlled by the cylinder manufacturer. Since 1977, all DOT 
specification cylinders manufactured outside the United States under 
the RSPA foreign cylinder approvals program are required to be 
inspected and certified by an IIA.
    In order to maintain the high level of safety established over the 
past 100 years, to maintain the acceptability of DOT specification 
cylinders worldwide, and to facilitate the harmonization between 
domestic and foreign cylinder specifications, RSPA is proposing that 
all cylinders manufactured or rebuilt to the new DOT metric-marked 
cylinder specifications be subject to inspection by an IIA. In effect, 
this would continue the current DOT inspection requirements for 
seamless cylinders and extend the practice to welded cylinders.

IV. DOT Approval of Cylinder Requalifiers

    RSPA proposes that any person who requalifies a DOT specification 
cylinder must be approved by the Associate Administrator prior to 
performing any requalification function that requires an inspection or 
retest date to be marked on the cylinder. The affected functions 
include performance of a visual inspection, pressure test, ultrasonic 
thickness test, repair, or the rebuilding of cylinders. This proposal 
will enhance the accountability of the cylinder requalification 
process.
    Currently, Sec. 173.34(e)(13) permits a cylinder used exclusively 
for certain liquefied gases to be requalified for use by performing an 
external visual inspection and marking the cylinder with the test date 
and an ``E''. The ``E'' indicates that the cylinder was requalified by 
external visual inspection in accordance with CGA Pamphlet C-6 rather 
than by a hydrostatic test. A person who performs only external visual 
inspections is not required to obtain an approval from, or register 
with, the Associate Administrator. Although current Sec. 173.34(e)(13) 
requires these persons to maintain records, RSPA does not know who or 
how many persons requalify and mark cylinders with an inspection date 
and an ``E'', or the locations of their places of business. Also, RSPA 
does not know whether these persons have the knowledge and skills 
necessary to perform the required functions, including use of required 
inspection standards.
    RSPA inspectors have frequently observed DOT specification 
cylinders, primarily in liquefied petroleum gas service, that bear 
markings representing that they were requalified for use. The markings 
reflected dates of recent requalification by external visual 
inspection. One cylinder, marked with the letter ``E'' and the date ``6 
98,'' was examined by RSPA personnel on June 19, 1998, and found to be 
rusted to an extent that there is no doubt that the rust formed long 
before the marked inspection date. Considering the amount of 
undisturbed rust on the cylinder, it was apparent that the person 
requalifying the cylinder did not properly prepare it for inspection by 
first completely removing all rust from the exterior surface of the 
cylinder, as required by paragraph 3.1 of CGA Pamphlet C-6, which was 
developed by the compressed gas industry for adoption by reference as 
Federal regulations.
    In reviewing the approach for resolving this issue, RSPA considered 
five options:
    (1) Continue the current provision that allows persons who are not 
known to RSPA to requalify cylinders by performing visual inspections;
    (2) Adopt a registration program that would require persons who 
perform visual requalification to be registered with RSPA and to mark 
their requalifier identification numbers (RIN) on the cylinders they 
inspect;
    (3) Adopt an approvals program requiring that persons performing 
requalifications of cylinders by visual inspection be approved by RSPA 
upon written application containing statements regarding their 
qualifications;
    (4) Adopt an approvals program that would require persons 
performing visual requalifications to be reviewed by an independent 
inspection agency; and
    (5) Discontinue visual requalification of cylinders, thereby 
requiring all affected cylinders to be hydrostatically retested.
    RSPA selected option 3 for this NPRM because it will not impose the 
burden and added cost of employing an independent inspection agency 
while ensuring the accountability of a person performing visual 
requalifications and providing RSPA the authority to revoke or suspend 
the person's approval for demonstrated non-compliance with the 
requalification requirements. Also, by requiring a certification that 
an applicant has the ability to perform requalifications, RSPA believes 
each applicant's awareness of the importance of compliance will be 
heightened. RSPA solicits comments on these options and others that 
RSPA may not have considered.

V. Requalification Markings

    RSPA proposes to amend Sec. 171.2(d) to prohibit the 
misrepresentation of a requalification identification number (RIN) 
marking. Over the years, through its compliance program, RSPA has been

[[Page 58465]]

in contact with dozens of individuals who did not perform the required 
hydrostatic tests, but stamped the cylinders as though each cylinder 
had passed the inspections and tests. The steel stamps used to mark the 
cylinders are readily available, low-cost and simple to use. RSPA 
believes that these and other factors (e.g., the high cost of 
purchasing and maintaining hydrostatic test equipment when compared to 
the mere cost of obtaining a set of steel stamps) provide an economic 
inducement for some individuals to engage in fraudulent activities. 
Based on recent enforcement data, this safety problem appears to be 
more widespread than RSPA originally thought. RSPA is concerned about 
the number of cylinders that are fraudulently stamped and then are used 
to transport hazardous materials in commerce. These cylinders, whose 
structural integrity has not been verified, pose substantial risks to 
health, safety and property. When RSPA discovers these situations, RSPA 
publishes a safety alert notice (see Notice No. 97-2, 62 FR 19651; 
Notice No. 97-3, 62 FR 24548) and, where appropriate, refers the matter 
to the Department of Justice for possible criminal prosecution (see 
United States v. American Oxygen Company, et al., Docket No. 97-533 
(D.N.M.)).
    RSPA is also soliciting comments on the issue of what future method 
or methods should be used to mark DOT specification cylinders during 
the requalification process. Currently, after a cylinder meets the 
requalification standards (e.g., passes a hydrostatic test, internal 
and external visual examinations, etc.), the requalifier stamps the 
month and year of the test and its RIN on the cylinder. This marking is 
normally accomplished with steel stamps (Note: currently under an 
exemption certain fiber-wrapped cylinders may be marked with labels.). 
Through this rulemaking, RSPA is evaluating the merits of new marking 
methods for DOT specification cylinders following the requalification 
process.
    RSPA is considering incorporating a number of marking options 
(e.g., labeling, marking with a laser, replacing the RIN with a symbol 
that is difficult to duplicate, etc.). RSPA is requesting comments from 
the public as to the feasibility, costs and benefits of alternatives to 
the metal stamping method and whether the public believes there is 
justification for RSPA adopting an alternative method.

VI. Toxic Gases

    Division 2.3 and 6.1, Hazard Zone A and B toxic inhalation hazard 
(TIH) materials present a substantial risk to the public, transport 
workers and emergency responders even when small quantities are 
released. For smaller cylinders, shifting freight and dropping are 
major sources of package damage and releases of hazardous materials. 
Cylinders are sometimes dropped in handling, resulting in valve damage 
or cylinder punctures. In a study of Hazardous Materials Information 
System (HMIS) reports for the past 10 years, RSPA found that over 30% 
of all reported cylinder incidents involved valve damage. Valve damage 
occurs when valves are inadequately protected by outer packagings or 
valve protection devices. Punctures most commonly occur when a cylinder 
is impacted by handling equipment or other cargo or is dropped upon 
other cargo or handling equipment. To reduce the probability that a 
handling incident may result in the release of a TIH material, RSPA 
proposes to expand the current drop test requirement for cylinders 
containing TIH materials to include Hazard Zone B materials and a 
performance test for cylinder puncture for TIH materials in Hazard 
Zones A and B. These proposed performance tests apply to bare cylinders 
and cylinders packed in strong outside packagings.
    The performance test for puncture is based upon dropping a cylinder 
seven feet; the same height used in the drop test for cylinder valve 
protection. The seven-foot drop height represents the typical distance 
that an industrial gas cylinder would encounter if it fell from a 
truck. RSPA chose an angle iron (2 inch by 2 inch by 0.25 inch thick) 
as a typical penetrator. The major parameters controlling cylinder 
penetration are cylinder material, wall thickness, drop height and the 
cylinder's gross weight. For consistency, RSPA proposes the cylinder 
weight be the water-filled weight. To represent in-service stress 
conditions, the proposed test is performed on the filled cylinder 
charged to service pressure for nonmetric-marked cylinders and 67% of 
test pressure for metric-marked cylinders.
    The puncture-performance test would be required for metric-marked 
and nonmetric-marked cylinders. To facilitate implementation of this 
requirement for nonmetric-marked cylinders, RSPA is proposing a two-
year implementation period. RSPA also proposes a table showing 
threshold values of wall thickness for cylinders of a particular 
specification, material, and water-filled weight range. Cylinders 
meeting the specified criteria with a minimum side wall thickness equal 
to or greater than the value specified in the table would qualify under 
current Sec. 173.40(d)(1) without puncture testing. To minimize the 
testing burden, RSPA plans to perform puncture testing to develop 
initial values for the table. RSPA is requesting that cylinder 
manufacturers and shippers assist RSPA in developing this table. RSPA 
is also soliciting comments on whether welded cylinders and cylinders 
with wall thickness of 2.0 mm or less are used for the transportation 
of Division 2.3 and 6.1 Hazard Zone B, C, and D materials. RSPA will 
use this information to further develop the puncture testing threshold 
table. When sufficient data is available, RSPA would consider the 
development of a graph or calculation as a more practical means to 
depict a minimum thickness threshold for puncture resistance.

VII. Discontinuation of Certain Cylinder Specifications

    RSPA proposes to discontinue the use of the following DOT cylinder 
specifications: 3C, 3D, 4, 4A, 4B240X, 4B240FLW, 4C, 9, 25, 26, 33, 38, 
40 and 41. RSPA believes that these cylinders are obsolete and no 
longer in general use. Authorization to manufacture these cylinders was 
removed from the regulations on September 11, 1980 (45 FR 59887). 
Comments are solicited from persons who may be using these cylinders.
    If the proposals contained in this NPRM lead to publication of a 
final rule, RSPA proposes to provide a transition period of five years 
from the effective date of the final rule for the continued 
construction of cylinders made to the following DOT specifications: 3A, 
3AX, 3AA, 3AAX, 3AL, 3B, 3T, 3BN, 4B, 4BA, 4BW, 4B240ET, and 4E. RSPA 
believes a five-year transition period for new construction of 
cylinders conforming to these specifications will reduce the burdens 
incurred by persons affected by this proposal. Cylinders made to these 
specifications would be authorized for continued use as long as they 
meet standards for periodic requalification. Voluntary compliance with 
the new metric or revised requirements would be authorized 90 days 
following publication of the final rule in the Federal Register.

VIII. Pressure Relief Device (PRD) Systems

    In a previous rulemaking (see, Docket No. HM-220A, 61 FR 26750, 
26756; May 28, 1996), RSPA proposed voluntary compliance with CGA 
Pamphlet S-1.1, paragraph 9.1.1.1, which would require verification 
that the PRDs operate properly. RSPA made this proposal based on the 
view that

[[Page 58466]]

over time certain components within a PRD will cease to function as 
designed. Thus, RSPA proposed adopting paragraph 9.1.1.1 which would 
have required that the operation of the PRD be verified. A number of 
commenters opposed this proposal citing its cost and the lack of 
incident data supporting adoption of this requirement. Based on the 
need to gather more data and review the cost estimates submitted, RSPA 
withdrew the proposal and agreed to consider the proposal in a future 
rulemaking. RSPA continues to evaluate adopting this industry standard.
    Since publication of HM-220A final rule, gas industry 
representatives have expressed the view that over time most polymers, 
used as seats in PRDs, vulcanize. Vulcanization prevents the devices 
from functioning as designed. RSPA solicits information on the 
following:
    1. Data and comments on the cost, effectiveness and need for 
adopting paragraph 9.1.1.1, in CGA Pamphlet S-1.1.
    2. Additional incident data from State and local officials 
concerning incidents that involved compressed gas cylinders which may 
not have been reported to RSPA because the incident did not involve a 
hazardous materials carrier or did not meet the reporting criteria 
specified in 49 CFR Sec. 171.16.
    3. Comments on the need to require PRD manufacturers to certify a 
performance range and period for their devices. Thus, a PRD would have 
to perform within specific limits throughout a specific life.
    Public comments that address these issues will be considered in a 
future rulemaking.

IX. Related Rulemakings, Petitions for Rulemaking, and Safety 
Recommendations

    Docket HM-176A (RIN 2131-AB51). RSPA proposes to amend Sec. 178.46 
to remove aluminum alloy 6351-T6 as an authorized material for the 
manufacture of DOT 3AL seamless cylinders. In January 1990, at RSPA's 
urging, manufacturers of DOT 3AL cylinders voluntarily discontinued the 
use of aluminum alloy 6351-T6 because cylinders made of this alloy are 
susceptible to cracks that could result in leaks or ruptures.
    On July 10, 1987, RSPA published in the Federal Register a safety 
advisory and advance notice of proposed rulemaking (ANPRM) (Docket No. 
HM-176-A; 52 FR 26027) to inform all persons possessing DOT 3AL (49 CFR 
178.46) cylinders, made of aluminum alloy 6351 manufactured by Luxfer 
USA Limited, that cracks had developed during service which 
occasionally resulted in leakage and loss of cylinder contents. In 
addition to the safety advisory, the notice identified those cylinders 
at risk, suggested steps that users should take to minimize risks, and 
requested industries' comments concerning the extent of the problem and 
their suggestions on corrective measures.
    RSPA received 31 comments from manufacturers, distributors, and 
industrial users of aluminum alloy cylinders. Some commenters submitted 
findings of studies for cylinders manufactured with aluminum alloy 
6351, including sustained load cracking (SLC) behavior testing. The 
majority of the comments and findings concluded that DOT 3AL cylinders 
made from aluminum alloy 6351, including cylinders authorized under 
exemption DOT-E 7235, pose a greater probability of failure than other 
cylinders. Further, information available to RSPA reveals that it is 
difficult to detect cracks in these cylinders which adds to the risks. 
RSPA published several notices to alert persons to the safety risk 
associated with cylinders manufactured to the DOT 3AL specification or 
under exemption DOT E-7235 and containing alloy 6351 (50 FR 32944, 
August 15, 1985; 58 FR 15895, March 24, 1993, 59 FR 38028, July 26, 
1994). Thus, there is sufficient data which demonstrates that this 
alloy is not suitable for the manufacture of compressed gas cylinders 
and that it should be removed as an authorized construction material.
    Petitions for rulemaking. RSPA has received numerous petitions for 
rulemaking requesting changes to the cylinder specifications and 
related commodity and requalification requirements. These petitions 
were held in abeyance and were considered in the development of this 
NPRM. Most of the requested changes are included in this NPRM. Because 
of the proposals in this NPRM to establish four new cylinder 
specifications and to discontinue construction of cylinders to certain 
current specifications, some of the requests for changes to the current 
regulations are no longer warranted. A summary of the petitions, with 
RSPA's comment shown in brackets, are as follows:

----------------------------------------------------------------------------------------------------------------
              Petition No.                                               Request
----------------------------------------------------------------------------------------------------------------
0095...................................  Consolidate the DOT 3-series specifications to permit unified
                                          specifications. Filed by CGA [Proposed in Secs.  178.69-178.73 for
                                          metric-marked cylinders].
0154...................................  Permit filling of non-toxic, nonliquefied flammable gases to 110% of
                                          the cylinder's marked service pressure (including hydrogen). Filed by
                                          CGA [Proposed in Sec.  173.302b for metric-marked cylinders].
0312...................................  Align rejection criteria of welded cylinder specifications to permit
                                          testing of second specimen from same lot if first specimen fails.
                                          Filed by the Canadian Transport Commission [Proposed in Sec.  178.81
                                          for metric-marked cylinders].
0324...................................  (Request same as P-0312). Filed by the Association of American
                                          Railroads.
0457...................................  Revise cylinder repair and rebuilding requirements. Filed by CGA
                                          [Proposed in Sec.  180.211 for all cylinders].
0553...................................  Amend Part 178 to change cylinder lot size in each specification. Filed
                                          by CGA [Proposed in Sec.  178.70 for seamless metric-marked cylinders
                                          and in Sec.  178.81 for metric-marked welded cylinders].
0652...................................  Revise Sec.  173.302(c)(3) table to add a fifth class of steel for DOT
                                          3 series cylinder tubes. Filed by CGA [Proposed in Sec.  178.70 for
                                          metric-marked cylinders].
0752...................................  Amend the table in 178.37-5(a), by adding a column titled ``Authorized
                                          Chemical analysis (designation 10B30).'' Filed by Pressed Steel Tank.
                                          (See DOT E 8311) [Proposed in Sec.  178.70 for metric-marked
                                          cylinders].
0823...................................  Incorporate by reference CGA Pamphlets C-1 and C-5. (See also P-981).
                                          Filed by CGA [Incorporated by reference in Sec.  171.7].
0866...................................  Revise required sequence for display of specification markings on
                                          seamless aluminum cylinders and allow use of new marking techniques
                                          [Proposed in Sec.  178.69 for metric-marked cylinders].
0953...................................  Establish a new specification for manufacture of new welded, stainless
                                          steel cylinders. (See E-4884). Filed by CGA [Proposed in Sec.  178.81
                                          DOT 4M specification].
1040...................................  Revise Sec.  173.304(c) and (d)(4) to expand specific gravities for
                                          LPG, at 42% filling density, from 0.504-510 to 0.497-0.510. Filed by
                                          the National Propane Gas Association [Proposed in Sec.  173.304b for
                                          metric-marked cylinders].
1071...................................  Permit use of DOT 3AL cylinders for any gas or gas mixture that is
                                          compatible with aluminum. Filed by CGA [Proposed greater use DOT 3ALM
                                          cylinders in Sec.  173.302b].

[[Page 58467]]

1082...................................  Revise 173.302(f) to remove 5/6 filling pressure limitation applicable
                                          to DOT 3AL cylinders. Filed by CGA [Proposed in Sec.  173.301a for DOT
                                          3AL cylinders and in Sec.  173.301b for DOT 3ALM cylinders].
1087...................................  Establish a new specification for seamless steel cylinders having a
                                          design stress of not more than 90,500 psi and a water capacity of not
                                          more than 150 pounds. (E-9001, 9370, 10047). Filed by CGA [Included in
                                          proposed new DOT 3FM specification in Sec.  178.73].
1090...................................  Require that a cylinder requalified by visual inspection must be marked
                                          with the retester's identification number. Filed by CGA [Proposed in
                                          Sec.  180.213].
1189...................................  Establish a new low pressure welded stainless steel cylinder
                                          specification. Filed by CGA. Includes P-0953 [Proposed in Sec.  178.81
                                          DOT 4M specification].
1229...................................  Revise Secs.  178.36 thru 178.60 to specify procedures for conducting
                                          tensile test. Filed by CGA [Proposed in Sec.  178.69 for metric-marked
                                          cylinders].
1233...................................  Permit nondestructive requalification testing of compressed natural gas
                                          (CNG) cylinders. Filed by FIBA [Proposed in Secs.  178.69, 180.207 and
                                          180.209 for metric-marked cylinders and certain nonmetric-marked
                                          cylinders].
1263...................................  Revise Sec.  173.34(e)(18) to permit the use of a permanent, non-
                                          transferrable label for retest and inspection markings on fire
                                          extinguishers. Filed by Amerex [Proposed in 180.213].
1277...................................  Revise Sec.  173.34(i)(4) to except DOT 4BW cylinders from heat
                                          treatment after replacement of nonpressure attachments. Filed by
                                          Manchester [Proposed in Sec.  180.211 subject to certain conditions].
----------------------------------------------------------------------------------------------------------------

National Transportation Safety Board (NTSB) Safety Recommendations.

I-92-001
    Recommends that RSPA require attachments to all DOT authorized 
hazardous materials packagings be designed to minimize the risk of 
puncturing other hazardous materials packagings during an accident 
situation. (Proposed in Sec. 173.301(m))
I-90-008
    Recommends that RSPA require hazardous material cargo to be secured 
in transportation with adequate restraint systems to prevent ejection 
of cargo from vehicles. (Proposed in Sec. 177.840)
I-90-009
    Recommends that RSPA require independent inspection of new and 
reconditioned low pressure cylinders that are consistent with present 
independent inspection requirements for high pressure cylinders 
[Proposed for 4M cylinders in Sec. 178.69.]

X. Cross Reference Table

    The following table lists the proposed paragraphs or sections and, 
where applicable, the corresponding paragraph or section contained in 
the current HMR. In some cases, the cross references are to provisions 
which are similar to, but not identical with current provisions.

------------------------------------------------------------------------
                New section                          Old section
------------------------------------------------------------------------
107.801
107.803(a)................................  173.300a(a).
  (b).....................................  173.300a, 173.34(e)(2)(ii)
                                             third sentence.
  (c) intro...............................  173.300a(b).
  (c)(1)..................................  (b)(2).
  (c)(2)..................................  (b)(3).
  (c)(3)..................................  (b)(6).
  (c)(4)..................................  (b)(7).
  (c)(5)..................................  (a).
  (c)(6)
  (c)(7)
  (d).....................................  (c), (i).
107.805(a)................................  173.34(e)(2)(ii).
  (b).....................................  (e)(2)(ii).
  (c).....................................  (e)(2)(ii)(A).
  (d).....................................  (e)(2)(ii)(B).
  (e).....................................  (e)(2)(ii)(B).
  (f)
107.807(a)................................  173.300b.
  (b).....................................  (b).
  (c).....................................  (g).
173.301(a)
  (a)(1)..................................  173.301(h).
  (a)(2)..................................  173.34(e)(1).
  (a)(3)..................................  (e)(17).
  (a)(4)..................................  (a)(2).
  (a)(5)..................................  (e)(1)(ii).
  (a)(6)..................................  173.301(k).
  (a)(7)
  (a)(8)
  (a)(9)
  (a)(10).................................  173.301(k).
  (b).....................................  173.34(c).
  (c).....................................  173.301(a).
  (d).....................................  (b).
  (e).....................................  173.34(c).
  (f).....................................  173.301(d).
  (g) intro
  (g)(1) thru (g) (3).....................  173.301(g)(1) thru (g)(3).
  (h).....................................  (g).
  (i)
  (j).....................................  (i).
  (k)
  (l).....................................  (j).
  (m)
173.301a(a)...............................  173.301(e).
  (b).....................................  (e)(1).
  (c).....................................  (e)(2).
  (d).....................................  (f) .
  (e).....................................  173.34(b).
173.301b
173.302(a)................................  173.302(a)(4), (a)(5)(i)
                                             thru (iii).
  (b).....................................  173.302(a)(4), (a)(5)(i)
                                             thru (iii).
  (c).....................................  173.301(e).
  (d).....................................  173.301(f).
173.302a(a) intro.........................  173.302(a).
  (a)(1)..................................  (a)(1).
  (a)(2)..................................  (a)(2).
  (a)(3)..................................  (a)(4).
  (a)(4)..................................  (a)(3).
  (a)(5)..................................  (a)(4) - (5).
  (b).....................................  (c).
  (c).....................................  (f).
  (d).....................................  (f).
  (e).....................................  (d).
173.302b
173.304(a)................................  173.304(a) intro, (a)(1).
  (a)(1)..................................  (a)(4).
  (a)(2)
  (a)(3)
  (b).....................................  (b).
  (c).....................................  (a) intro.
  (d).....................................  (e).
  (e).....................................  (f).
173.304a(a)...............................  173.304(a).
  (c).....................................  (c).
  (d).....................................  (d) .
  (e).....................................  (h).
173.304b
173.315(p)................................  173.301(d)(5).
180.201
180.203
180.205(a)
  (b).....................................  173.34 (e)(2).
  (c) intro...............................  (e)(1).
  (c)(1)..................................  (e)(1).
  (c)(2)
  (c)(3)..................................  (c)(3).
  (c)(4)
  (d)
  (e).....................................  (e)(17).
  (f).....................................  (e)(3).
  (g).....................................  (e)(4).
  (h).....................................  (e)(5).
  (i).....................................  (e)(6).
180.207
180.209(a)................................  173.34(e) intro.
  (b).....................................  (e)(16).
  (c).....................................  (e)(9).
  (d).....................................  (e)(10).
  (e).....................................  (e)(11).
  (f).....................................  (e)(12).
  (g).....................................  (e)(13).
  (h).....................................  (e)(14).
  (i).....................................  (e)(18).
  (j).....................................  (e)(19).
  (k)
180.211...................................  173.34(g), (i) through (l).
180.213...................................  173.34(c), (e)(7).

[[Page 58468]]

180.215...................................  173.34(e)(2)(v), (e)(8),
                                             (e)(13).
------------------------------------------------------------------------

XI. Summary of Regulatory Changes by Section

Part 107, Subpart I

Section 107.801-107.807

    This new subpart would contain procedures whereby persons may seek 
approval from the Associate Administrator to be a cylinder requalifer, 
an independent inspection agency (IIA), or to have chemical tests or 
analysis performed outside the United States for DOT specification 
cylinders manufactured outside the United States. These requirements 
are contained currently in Secs. 173.300a, 173.34(e) and 173.300b, 
respectively. This new subpart would contain the specific requirements. 
Current requirements in 49 CFR Subpart H of Part 107 would be 
referenced for minimum content of an application, the RSPA office where 
an application is to be filed, and the procedures that will be used to 
process or terminate an application for approval.
    The criteria permit the selection of any person or organization, 
foreign as well as domestic, that is technically competent to perform 
the prescribed functions and is free from undue influence by persons 
involved with the fabrication, ownership or movement of the cylinders 
that the applicant, if approved, would be called upon to evaluate and 
certify. Under this proposal, RSPA would accept for transportation in 
the United States foreign-made cylinders that are similar in 
construction to the proposed DOT metric-marked cylinders. As part of 
this policy, if the United States recognizes cylinders manufactured 
outside the United States and approved by a third party inspector 
approved by another government, then equal treatment is expected of 
that government relative to cylinders manufactured in the United States 
and approved by an IIA approved by DOT. Therefore, a foreign third-
party inspector, who certifies cylinders manufactured outside the 
United States, must submit a statement from the competent authority of 
the foreign government stating that similar authority is delegated to 
manufacturers of metric-marked cylinders in the United States and that 
no additional limitations are imposed.
    Proposed Sec. 107.803 (current Sec. 173.300a) prescribes 
application procedures for approval or renewal as an IIA. These 
procedures, contained currently in Sec. 173.300a, would also permit an 
IIA, upon approval by the Associate Administrator, to perform other 
functions relating to the cylinder requalification requirements 
prescribed in Part 180.
    Proposed Sec. 107.805 (current Sec. 173.34(e)(2)) prescribes 
application procedures for a person seeking an approval to perform 
periodic cylinder requalifications. The procedures would be revised and 
broadened to apply to any person who performs a function after which 
the cylinder is required to be marked with a date as discussed in Part 
IV of this preamble under the heading ``DOT approval of cylinder 
requalifiers''. Because these provisions would be expanded to apply to 
repairers and rebuilders, the terms ``retester'' and ``retester 
identification number'' would be replaced with the terms 
``requalifier'' and ``requalifier identification number,'' 
respectively.
    Proposed Sec. 107.807 (current Sec. 173.300b) prescribes the 
application procedures for issuance or renewal of an approval to 
perform chemical analyses and tests outside the United States on DOT 
specification cylinders manufactured outside the United States.

Part 171

Section 171.2

    Paragraph (d)(3) would be amended to clarify that no one may mark a 
requalifier identification number on a cylinder that has not been 
requalified in accordance with the applicable requirements.

Section 171.7

    This section would incorporate the latest editions of previously 
approved CGA Pamphlets, incorporate certain additional ASTM and CGA 
standards, and add references to certain publications of the American 
National Standards Institute (ANSI).

Section 171.8

    Definitions for ``metric-marked cylinder'' and ``nonmetric-marked 
cylinder'' would be added.

Section 171.12

    Paragraph (b)(15) would be revised to include references to 
Sec. 171.12a(b)(13).

Section 171.12a

    On August 18, 1998, RSPA issued a notice of proposed rulemaking 
[Docket HM-215C; 63 FR 44312] which proposed to revise paragraph 
(b)(13) to provide reciprocity for certain Canadian specification 
cylinders to be transported within the United States. This HM-215C 
proposed change is reprinted here for the benefit of readers.

Part 172

    In the Sec. 172.101 Table, in column (8b) for the entries 
``Cyanogen'', ``Germane'', and ``Iron Pentacarbonyl'' would be revised 
to specify packaging authorization sections that are consistent with 
their toxic properties.

Part 173

Section 173.34

    The provisions in this section would be relocated to subpart I of 
part 107, Sec. 173.301 and subpart B of part 180, as appropriate, and 
Sec. 173.34 would be removed. All references to Sec. 173.34 in the HMR, 
approximately 150 in number, would be removed and replaced with the 
appropriate section reference.

Section 173.40

    The requirements for toxic materials packaged in cylinders would be 
revised to include an additional performance criteria for puncture 
resistance. The requirements in Sec. 173.40 currently apply only to 
materials in Hazard Zone A. All requirements except the controls on 
closures would be expanded to Hazard Zone B materials. RSPA requests 
comments on whether cylinders with Hazard Zone B materials should be 
required to meet the same closure requirements required for Hazard Zone 
A.
    As discussed earlier in this preamble, DOT 3AL cylinders made of 
aluminum alloy 6351-T6 are susceptible to sustained load cracking (SLC) 
in the neck and shoulder area of the cylinder head and, therefore, may 
leak in transportation. Leaks of Toxic Inhalation Hazard (TIH) 
materials pose a significant threat to health and safety. At least two 
major gas suppliers have voluntarily stopped using these cylinders in 
TIH gas services. The proposed regulation will reduce the risk to 
health and safety associated with TIH materials leaking through cracks 
in cylinders. RSPA proposes that this regulation be imposed on the 
effective date of this rule. After that date, cylinders made of 6351 
alloy may not be filled and offered for transportation in TIH service. 
Cylinders filled prior to that date may be offered for transportation 
and transported to their ultimate destination and, when necessary, 
cylinders containing unused gas may be returned to the person who 
filled the cylinder.

Section 173.163

    The requirements for nonmetric-marked cylinders containing hydrogen 
fluoride would be amended to require ultrasonic examination as the only 
authorized requalification method. This

[[Page 58469]]

proposal is based on the fact that the presence of moisture in a 
cylinder containing hydrogen fluoride causes rapid corrosion of the 
cylinder wall. Since removal of all moisture after hydrostatic testing 
is very difficult, the current requirements authorize only the external 
visual inspection in lieu of hydrostatic testing and internal visual 
inspection. At the time the requirement was last amended, no other 
alternative examination was available to reliably examine the cylinder 
without introducing moisture into the cylinder. An ultrasonic 
examination, to examine the internal sidewall for defects, can be 
performed without introducing moisture to the cylinder. This section 
also would be amended to include metric-marked cylinders for use in 
hydrogen fluoride service.

Section 173.192

    The title of this section would be revised to reflect that 
requirements are applicable to Hazard Zone A gases. The restriction on 
aluminum cylinders by highway and rail would be extended beyond arsine 
and phosphine to include all Hazard Zone A gases. Paragraph (c) would 
be amended to authorize alternative leakage tests having an equivalent 
level of sensitivity as the current water bath leakage test, upon 
written approval from the Associate Administrator. Currently without 
exception, cylinders containing any amount of phosgene gas must be 
subjected to a water bath leakage test prior to offering them for 
transportation.

Section 173.198

    An editorial change would be made to paragraph (a).

Section 173.226

    Paragraph (a) would be revised to include only seamless 
specification cylinders conforming to all requirements of Sec. 173.40. 
Currently, Division 6.1, Hazard Zone A materials may be shipped in any 
DOT specification cylinder except 8, 8AL and 39. RSPA believes that 
this must be corrected in order to require these high hazard materials 
to be transported in cylinders with a higher level of safety.

Section 173.227

    Paragraph (a) would be revised to include only seamless and welded 
specification cylinders conforming to the requirements of Sec. 173.40.

Section 173.228

    Paragraph (a) would be amended to include metric-marked 
specification cylinders and to require that cylinders used for bromine 
pentafluoride and bromine trifluoride in Hazard Zones A and B materials 
must conform to Sec. 173.40 as required for similar materials.

Sections 173.300a-173.300c

    The provisions in these sections would be relocated to new Subpart 
I of Part 107 and Secs. 173.300a, 173.300b and 173.300c would be 
removed.

Sections 173.301-173.301b

    Current Sec. 173.301 would be revised and proposed Secs. 173.301a 
and 173.301b would be added. Section 173.301 would contain the general 
shipper requirements for the use of specification cylinders that are 
currently in Sec. 173.34 and the standard requirements for cylinders 
that are currently in Sec. 173.301. These requirements include general 
prefill requirements, maintenance and legibility of markings, PRD, 
valve protection, manifolding of cylinders and the charging of foreign 
cylinders. A derivation table showing the relocation of the 
requirements appears in Part X of this preamble.
    Certain other changes would be made to Sec. 173.301. The cargo tank 
manifolding requirements that are currently in Sec. 173.301(d) would be 
removed and placed with other cargo tank requirements in Sec. 173.315.
    Proposed paragraph (a)(6) would prohibit the offering for 
transportation and transportation in commerce of a filled cylinder 
having a specified service life after its service life has expired. 
This requirement will ensure cylinders that may be unsafe are removed 
from service for transportation of hazardous materials.
    Proposed paragraph (d) contains the general prohibition, that is 
currently contained in paragraph (a), against filling a cylinder with 
gases that are capable of combining chemically with each other or with 
the cylinder material so as to endanger its serviceability. This 
provision would be expanded to prohibit the use of DOT 3AL cylinders 
made of aluminum alloy 6351-T6 for gases having pyrophoric properties. 
Leaks of gases having pyrophoric properties, such as, silane, would 
cause spontaneous flame and pose a significant threat to the health and 
safety. A transition period of six months after the effective date of 
the final rule would be provided for cylinders filled prior to the 
specified date.
    Proposed paragraph (f) contains PRD system and setting 
requirements. The general purpose of a hazardous material packaging is 
to prevent the unintentional release of a hazardous material under 
normal conditions of transportation, including mishandling and minor 
traffic accidents. Also, the packaging standards for cylinders are 
designed to prevent failure of a cylinder from over pressurization, 
particularly, when it retains substantial stored energy. Thus, a 
balance must be set between competing interests for keeping a hazardous 
material, particularly Division 2.1 and 2.3 gases and Division 2.2 
gases with oxidizing properties, in a packaging and allowing such a 
material to escape in order to prevent the packaging from rupturing.
    Under current regulations, the type and setting of PRD systems are 
established by CGA Pamphlet S-1.1. CGA Pamphlet S-1.1 allows a PRD 
setting to be 75% to 100% of test pressure of the cylinder. Based on 
RSPA's analysis of the currently authorized settings, a fully charged 
nonmetric-marked DOT-3 series gas cylinder at 130  deg.F operating 
temperature will likely release hazardous gases when the PRDs, 
conforming to the authorized tolerances on device function, are set 
below test pressure. RSPA believes this creates a serious threat to 
safety by allowing an improper balance between keeping the hazardous 
material in the package and preventing the cylinder from rupturing. In 
contrast, RSPA does not believe this condition applies to DOT-4 series 
cylinders because the ratio of test pressure to service pressure is 2:1 
as compared to 1.67:1 for DOT-3 series cylinders.
    To correct this condition, RSPA is proposing a PRD setting of 100% 
of the marked test pressure for metric-marked and nonmetric-marked DOT-
3 series cylinders. To allow users sufficient time to change their 
nonmetric-marked cylinders to meet the new PRD setting requirement, 
RSPA is proposing that each cylinder be brought into compliance at the 
first requalification of the cylinder after the effective date of the 
final rule.
    RSPA believes a setting of 100% of test pressure for a PRD is a 
reasonable balance between keeping a gas in a cylinder and preventing a 
cylinder from rupturing in the event of a fire or overfill. PRDs 
designed to release at not less than test pressure will eliminate the 
possibility of gas release through the relief device at a temperature 
less than or equal to 54  deg.C (130  deg.F). At the same condition, 
test pressure, the factor of safety for cylinder rupture is 1.6. As a 
result of discussions with gas shippers, RSPA believes many major 
shippers of DOT-3 series cylinders are currently setting PRDs at 90-
100% of test pressure for toxic and flammable gases. Because it is 
common practice for many shippers of DOT-3 series cylinders to replace 
the PRD at the time of a

[[Page 58470]]

cylinder's requalification, RSPA believes the proposal will result in 
minimal incremental cost. For most gases, RSPA believes the increased 
PRD setting will not significantly impact the performance of cylinders 
in bonfire tests. RSPA requests the following:
    1. Data on the performance of PRDs set at test pressure in bonfire 
tests.
    2. Comments on any gases or cylinders where a 100% of test pressure 
setting could prevent a cylinder from passing a bonfire test.
    3. Comments on the need to requalify PRDs in a bonfire test.
    Proposed paragraph (h) would contain the cylinder valve protection 
requirements that are currently in paragraph (g). These requirements 
would be revised to require a performance-oriented approach to valve 
assembly protection. A six foot drop test would be required to verify 
that each cylinder valve (with or without protection assembly) has 
sufficient strength to survive falls incidental to handling in 
transportation. An acceptable drop test result would be that no leakage 
occurs after the cylinder is dropped, although the cylinder may show 
damage. A similar drop test is currently required for all non-bulk 
performance-oriented packagings to ensure that the packages can 
withstand normal conditions of transportation. RSPA believes that 
cylinders should be held to at least the same level of performance as 
drums and fiberboard boxes. A period of five years is proposed in 
paragraph (h)(1)(i) to provide a smooth transition to meet this 
performance requirement.
    Proposed paragraph (k) would be added to permit foreign cylinders 
to be imported into the United States and transported within a single 
port area subject to certain conditions.
    Proposed paragraph(m) would be added to prohibit cylinder 
attachments with sharp features that may cause damage to other freight. 
This new provision is in response to NTSB Recommendation I-92-001 with 
respect to cylinders. Attachments for other hazardous material 
packaging types will be addressed in a separate rulemaking action.
    Proposed Sec. 173.301a would contain the current requirements 
pertaining to the pressure in a nonmetric-marked cylinder at 70  deg.F 
and 130  deg.F. It would also contain a grandfather provision that is 
currently in Sec. 173.34(b).
    Proposed Sec. 173.301b contains additional general requirements for 
metric-marked cylinders used for nonliquefied (permanent) gases. 
Definitions would be added for ``critical temperature,'' ``dissolved 
gas,'' ``filling factor of liquefied compressed gas,'' ``high pressure 
liquefied compressed gas,'' ``low pressure liquefied compressed gas,'' 
``permanent (non-liquefied compressed) gas,'' ``safety factor,'' and 
``settled pressure.'' These proposed definitions, which are used in ISO 
Standard 11622, will provide for harmonization with the international 
standards.

Sections 173.302-173.302b

    Current Sec. 173.302 would be revised and proposed Secs. 173.302a 
and 173.302b would be added. Proposed Sec. 173.302 prescribes the 
general requirements that would apply to filling a specification 
cylinder with a nonliquefied (permanent) compressed gas.
    Proposed 173.302a prescribes requirements for filling a nonmetric-
marked cylinder with a nonliquefied compressed gas, i.e., the current 
requirements in Sec. 173.302. In addition, RSPA proposes to remove the 
\5/6\ filling pressure limitation for DOT 3AL cylinders in carbon 
monoxide service, in response to a CGA petition (P-1082). CGA furnished 
information to support its conclusion that, although evidence shows 
that carbon monoxide can cause stress corrosion cracking in steel 
cylinders, there is no evidence that carbon monoxide causes corrosion 
cracking or carbonyl formation in aluminum cylinders.
    Proposed Sec. 173.302b prescribes requirements for filling a 
metric-marked cylinder with permanent gas. Because a metric-marked 
cylinder is stamped with the test pressure in bar, the fill pressure is 
calculated from the marked test pressure. The charge pressure for a 
metric-marked cylinder is \2/3\ of the test pressure for seamless DOT 
3M, 3FM and 3ALM cylinders, and \1/2\ of the test pressure for welded 
DOT 4M cylinders. The NPRM proposes a uniform standard which reduces 
the possibility of overfilling and allows the gas industry to ship an 
additional 1.5% gas. Because the NPRM proposes that the cylinder be 
marked and charged in accordance with ISO Standard 11622, it would 
facilitate shipments of hazardous material in DOT specification 
cylinders internationally.

Section 173.304-173.304b

    Current Sec. 173.304 would be revised and proposed Secs. 173.304a 
and 173.304b would be added. Proposed Sec. 173.304 prescribes general 
requirements that would apply to filling a specification cylinder with 
a liquefied gas.
    Proposed Sec. 173.304a prescribes specific requirements for filling 
a nonmetric-marked cylinder with a liquefied gas, i.e., the 
requirements that are currently in Sec. 173.304. Currently, 
Sec. 173.304 limits the filling of a cylinder with a liquefied 
compressed gas based on the maximum expected operating temperature (130 
 deg.F) and the minimum specific gravity of the liquid at 60  deg.F. 
The maximum filling densities for many gases are prescribed in a table 
that would be retained in the HMR in Sec. 173.304a for nonmetric-marked 
cylinders.
    The current regulation defines a liquefied compressed gas to be 
partially liquid at an operating temperature of 20  deg.C (68  deg.F) 
and authorizes a filling limit based on a wide range of critical 
temperatures. Therefore, the safety factor derived from filling limits 
is conservative for some gases and marginal for other gases. In 
addition, the current regulations limit the internal volume of a DOT-39 
specification cylinder to 75 cubic inches when used for liquefied 
petroleum gases. This requirement is revised to apply to all liquefied 
flammable gases and appears in proposed Sec. 173.304a(a)(3). In 
proposed Sec. 173.304b for metric-marked cylinders, filling limits are 
based on the maximum operating temperature and filling factor. Instead 
of a maximum filling density table, the proposed filling limits are 
based on a filling factor which is directly related to the critical 
temperature of the liquefied compressed gas. The proposed filling 
limits are applicable to all liquefied compressed gases. Under the 
proposed filling limits, the filling factor is defined based on the 
critical temperature and the operating condition of each individual 
gas. Therefore, the proposal enhances the level of safety and allows 
the gas industry to fill the cylinders with more product.

Section 173.334

    This section would be amended to include metric-marked 
specification cylinders.

Section 173.336

    This section would be amended to include metric-marked 
specification cylinders.

Section 173.337

    This section would be amended to include metric-marked 
specification cylinders.

Part 177

Sec. 177.840 Class 2 (Gases) Materials

    RSPA proposes to revise paragraph (a)(1) to allow horizontal 
loading of cylinders containing Class 2.2 materials. In addition, the 
horizontal loading of Class 2.1 and Class 2.3 materials would be 
permitted for cylinders designed so that the inlet to the PRD is 
located in the

[[Page 58471]]

vapor space and provided that the cylinders are properly secured during 
transportation.
    This paragraph also would require the use of cylinder restraint 
systems to reduce the likelihood of the cylinders being ejected from 
the vehicle in event of an accident. This proposal is based on a NTSB 
Recommendation I-90-008, that urges RSPA to require hazardous materials 
packages to be secured with adequate cargo restraint systems to prevent 
their ejection from the vehicle during transportation. NTSB made the 
recommendation following an accident in Collier County, Florida that 
involved a number of cylinders, containing a poisonous by inhalation 
gas, being ejected from an overturned tractor-flatbed semitrailer. 
Considering the wide variation in cylinder sizes, and the various types 
of restraints that would be required, RSPA solicits information on 
anticipated safety benefits and the costs of requiring the use of 
restraint systems, particularly on small businesses.

Part 178

Section 178.46

    As discussed in Part IX of this preamble, the tables in paragraph 
(b)(4) would be revised to remove aluminum alloy 6351 as an authorized 
material for the manufacture of DOT 3AL seamless cylinders. In 
addition, in Table 1, several changes would be made to the chemical 
composition limits for 6061 alloy for consistency with limits stated in 
The Aluminum Association Standards and Data, 1993 edition. The Si 
maximum that is currently stated as 0.80% would be revised to read 
0.8%, the Fe maximum that is currently stated as 0.70% would be revised 
to read 0.7%, the Mg minimum that is currently stated as 0.80% would be 
revised to read 0.8%, and the Mg maximum that is currently stated as 
1.20% would be revised to read 1.2%. Finally, Table 1 limits the 
chemical composition of Pb (lead) and Bi(bismuth) to 0.01. RSPA 
proposes to change these limits to 0.005.

Section 178.69

    This new proposed section contains general design and manufacturing 
requirements applicable to all metric-marked DOT specification 
cylinders. This proposed section contains much of the same information 
as the current Sec. 178.35, including compliance, inspection and 
analyses, duties of inspector, PRDs, and markings; however, proposed 
Sec. 178.69 is extended to address definitions, authorized material, 
threads, and tests. Thus, Sec. 178.69 would simplify the regulations in 
that all information common to metric-marked cylinders will be 
centrally located, and will allow the simplification and streamlining 
of the individual cylinder specifications proposed in Secs. 178.71, 
178.72, 178.73 and 178.81.
    Paragraph (b) will define common terms for clarity and consistency. 
The addition of the new definition for ``volumetric expansion test'' 
will clarify RSPA's meaning of the many terms used by industry to 
describe pressure testing.
    Paragraph (c) specifies the requirements for inspection and 
analyses. RSPA proposes that all DOT 4-series metric-marked cylinders 
have inspection and analyses performed by an independent inspection 
agency.
    In paragraph (e), duties of the inspector, RSPA proposes a change 
to allow the inspector to obtain a certified cast or heat analysis from 
the cylinder manufacturer in addition to the material producer or 
supplier, as needed. The current regulations require the inspector to 
verify that the material of construction meets the requirements of the 
applicable specification by either making a chemical analysis of each 
heat of material; obtaining a certified chemical analysis from the 
material manufacturer for each heat of material; or by making a check 
analysis of a sample from each coil, sheet, or tube if an analysis is 
not provided by the material manufacturer for each heat of material. 
These alternative methods for verifying compliance are something raised 
by independent inspectors to require cylinder manufacturers to perform 
check analyses when readily available information may be used. The 
proposed regulation would allow cylinder manufacturers to use analyses 
obtained from the mill to verify the material conforms to standards for 
the cylinder specification.
    Paragraph (f) specifies performance-oriented requirements for 
threads. These requirements would allow the manufacturer to design the 
threads in conformance with any appropriate standard as long as certain 
thread shear strength limits are met.
    Paragraphs (h) and (i) list all tests that apply to metric-marked 
cylinders. A new approach for the metric-marked cylinders is the 
categorization of design qualification tests (paragraph (h) in addition 
to production tests in paragraph (i)). These paragraphs include 
criteria for each test as well as acceptance criteria. The individual 
cylinder specifications prescribe which tests in Sec. 178.69 apply to 
each specification, as well as any unique test requirements or 
acceptable results. Centralizing all test information in one location 
reduces repetition in the regulations and reduces the likelihood of 
inconsistent requirements in the specifications. The requirement that 
new metric-marked cylinders have cycle testing performed during design 
qualification incorporates current industry practice. RSPA believes 
that the cycle test is an important design performance test that 
assesses cylinder fatigue life and, therefore also, proposes this 
requirement for welded cylinders.
    Paragraph (i)(12) contains requirements for ultrasonic examination 
(UT); a non-destructive test method designed to detect surface and 
subsurface flaws and to measure the thickness of a cylinder and the 
size of a flaw or crack. The UT equipment has the capability to detect 
the presence of discontinuities on or even within the cylinder 
sidewall, shoulder, or bottom. UT would be required for all seamless 
and some welded metric-marked cylinders at the time of manufacture.
    Paragraph (k) prescribes marking requirements. A significant change 
for the new metric-marked cylinders is marking with the test pressure, 
rather than service pressure, expressed in bar. To communicate vital 
information to requalifiers, metric-marked cylinders that require UT 
examination during requalification must be marked ``UT'' as well as 
with the minimum wall thickness. Other markings, such as country of 
origin, will be required for metric-marked cylinders; thereby making 
them more acceptable for transportation of hazardous materials in 
international commerce.
    Paragraph (l) includes a prohibition on coatings that may interfere 
with inspections and tests, or that allow moisture to accumulate 
between the cylinder wall and the coating. This provision is RSPA's 
response to potential threats to safety associated with coating 
materials, such as vinyl, which promote corrosion.

Section 178.70

    This proposed section groups the common requirements that apply to 
all DOT 3 series metric-marked seamless cylinders (DOT 3M, DOT 3ALM, 
and DOT 3FM).
    Paragraph (c) specifies materials for 3 series cylinders. 
Authorized materials are located in Appendix A, Table 1 for steel and 
nickel and Table 2 for aluminum. The steel compositions authorized 
include two carbon manganese type, one chrome moly type steel, and one 
stainless steel type. The aluminum composition is a 6061 alloy. These 
compositions are broad enough to cover most material specifications 
currently in use.

[[Page 58472]]

    Paragraph (e) specifies wall thickness requirements. The current 
DOT 3AAX requirement in Sec. 178.37(a)(2)(i) that adresses additional 
design loads due to bending is proposed in this general section for all 
DOT 3-series metric-marked cylinders. The inclusion of this requirement 
sets a precedent in the HMR by allowing manufacturers the flexibility 
to adapt any metric-marked cylinder specification to a ``tube trailer'' 
type cylinder.

Section 178.71

    This section proposes the new DOT 3M metric-marked cylinder 
specification. This specification combines aspects of the current DOT 
3A, 3AX, 3AA, 3AAX, 3B, and 3BN specifications.
    Proposed paragraph (c) authorizes construction using steel, 
stainless steel, and nickel. The carbon manganese composition 
authorized encompasses the steel currently used for DOT 3A 
specification cylinders. The inclusion of the stainless steel 
composition for a seamless cylinder will eliminate the need for many 
exemptions.

Section 178.72

    This section proposes the new DOT 3ALM metric cylinder 
specification. This specification is very similar to the current DOT 
3AL except that aluminum alloy 6351 is not authorized as a material of 
construction.

Section 178.73

    This section proposes the new DOT 3FM metric-marked cylinder 
specification. The proposed DOT 3FM cylinder is designed to a high 
stress level similar to the DOT 3T, and incorporates the strong 
structural integrity of the DOT 3AA cylinder. This specification meets 
many of the requirements of the ISO Standard 9809-2 cylinder, which 
should make it readily acceptable in international commerce. The 
authorized materials of construction are Grade B, a chrome molybdenum 
type steel currently authorized for 3T cylinders and Grade E a new 
chrome molybdenum type steel. Steels such as Grade E with higher 
ultimate strength levels (above 115,000 psi) are currently authorized 
under exemption. Because the most critical failure mode is cracking, 
these cylinders will be subjected to UT examination at the time of 
manufacture and requalification.

Section 178.81

    This section contains specific requirements for the proposed DOT 4M 
metric-marked cylinder specification. This specification combines 
aspects of the current DOT 4B, 4BA, 4BW, 4B240ET, 4E, 4D, 4DA, 4DS and 
4AA480 specifications. The maximum design test pressure is 140 bar 
(2030 psi). This represents a pressure of more than double what is 
currently authorized for welded cylinders, except the DOT 4DA and 4DS 
specification, which have a maximum test pressure of 1800 psi. 
Authorized materials would include aluminum alloy 5154 currently used 
for the DOT 4E specification cylinder, as well as carbon, HSLA, 
stainless, and 4130X steels. For DOT 4M specification cylinders with a 
test pressure of 70 bar or more, the welds must be 100% radiographed to 
provide assurance of the joint quality. Manufacturers of DOT 4M 
specification cylinders would have the option of performing an 
ultrasonic examination in lieu of the radiographic examination.
    RSPA solicits comments on the need for a higher performance welded 
cylinder specification than what is proposed in this NPRM. Comments are 
also requested as to whether such a higher performance specification 
should be distinguished from the lower performance by pressure, or by 
material strength, or some other performance standard. RSPA is 
currently considering a cylinder specification with a design test 
pressure of either more than 140 bar (2030 psi) or with an ultimate 
tensile strength of 830 Mpa (121,000 psi) or higher.

Part 180

Part 180, Subpart C

    This new subpart would prescribe requirements for the continuing 
qualification, maintenance, repair and rebuilding of DOT specification 
and exemption cylinders. Most of the requirements are currently 
contained in Secs. 173.34 and 173.301. Readers should refer to the 
references under Part X of this preamble for the citation of the 
corresponding provision that is similar to the current provision 
contained in the HMR. The proposed requirements include DOT metric-
marked cylinders.

Section 180.203

    This section contains definitions for terms used throughout Subpart 
C. Some of these definitions are ``commercially free of corrosive 
components,'' ``condemn,'' ``defect,'' ``rejected cylinder,'' and 
``volumetric expansion test.''

Section 180.205

    This section prescribes general requirements for the continuing 
qualification and use of cylinders and for each person performing a 
cylinder requalification function.

Section 180.207

    This section prescribes requirements for the periodic 
requalification of metric-marked specification cylinders. Proposed 
Table I specifies the periodic requalification requirements. The 
standard requalification period is once every five years, with extended 
requalification periods provided for cylinders used exclusively to 
transport certain gases. For example, when used exclusively for 
noncorrosive, nontoxic (LC50 of not less than 5000 ppm) gases, DOT 3M, 
3ALM, and 3FM specification cylinders must be requalified at least once 
every ten years. Similarly, a DOT 4M specification cylinder must be 
requalified at least once every 15 years. DOT 3M and 4M specification 
cylinders used exclusively as fire extinguishers and meeting the 
limitation of special provision 18 must be requalified at least once 
every twelve years, as currently required for nonmetric-marked DOT 
specification cylinders used as fire extinguishers.
    All DOT 3M, 3ALM, 3FM and 4M specification cylinders must be 
requalified using the ultrasonic examination, instead of a volumetric 
expansion test. A DOT 4M specification cylinder, with a marked test 
pressure of 70 bar or less and having a tensile strength less than 830 
Kpa (120,000 psi), may be subjected to a volumetric expansion test in 
lieu of an ultrasonic examination. Ultrasonic examination improves 
safety by automating the identification and measurement of wall 
thickness, pitting and cracking. It improves the probability of 
detection for internal pits and cracks over current internal visual 
inspection. Ultrasonic examination also reduces inspection and labor 
costs, cleaning costs and waste water by allowing cylinder 
requalification without removing the valve and purging the cylinder's 
contents, and without the deliberate introduction of water into the 
cylinder.
    Comments are invited on the proposed requirements for ultrasonic 
examination of cylinders. RSPA also solicits information on industry 
practices in this area, the costs and benefits for using UT 
examinations and the pass/fail criteria in Table II.

Section 180.209

    This section prescribes requirements that are currently contained 
in Sec. 173.34(e) for the periodic requalification of nonmetric-marked 
specification cylinders. The current rule for the requalification of 
most DOT specification and exemption cylinders requires a volumetric 
expansion test, external and internal visual inspections

[[Page 58473]]

which are not suitable for detecting a buried or internal crack.
    In proposed paragraph (a)(1), note 2 following the table requires 
detection and measurement of the sidewall cracks in DOT 3T and 3HT 
cylinders at each requalification period by an approved non-destructive 
test (NDT) method. Cracks in these cylinders can be detected by using a 
suitable NDT method, such as acoustic emissions or appropriate shear 
wave ultrasonic examination. Because the ultimate tensile strength 
(UTS) of DOT 3T and 3HT cylinders are above 7,900 Mpa (155,000 psi), 
crack growth due to stress corrosion and fatigue can occur during 
normal service. An undetected crack can grow to a critical size and 
result in a catastrophic failure. Manufacturers of specificition DOT 3T 
and other high strength exemption cylinders are required to perform UT 
examinations at the time of manufacture.
    Proposed paragraph (a)(2) allows for nonmetric-marked specification 
cylinders to be ultrasonically examined as an alternative 
requalification method. An external visual inspection is required to be 
conducted in conjunction with the UT examination. The requalification 
period for nonmetric-marked cylinders is the same as required in Table 
I of this proposed section.

Section 180.211

    This section prescribes repair, rebuild and heat treatment 
requirements currently prescribed in Secs. 173.34(g) thru 173.34(l), 
with certain revisions. These requirements are standardized and 
simplified.

Section 180.213

    This section contains marking requirements presently contained in 
Sec. 173.34(e)(7), with certain revisions.
    A new requirement for all specification cylinders would be added to 
identify the type of inspection, test, or work performed on a cylinder. 
This new requirement would enable shippers, carriers, and enforcement 
personnel to readily determine the type and date of each inspection or 
test, or whether any repair or rebuilding work has been performed on a 
cylinder.
    The methods for marking cylinders would permit stamping, engraving, 
scribing or any other method approved in writing by the Associate 
Administrator for HMS. In response to a NPGA petition, RSPA also 
proposes allowing use of pressure sensitive labels to display the 
requalification markings on fire extinguishers. However, RSPA is also 
soliciting comments on whether there are any methods that should or 
should not be authorized for application of requalification markings. 
Currently, after a cylinder passes the requalification volumetric 
expansion test, internal and external visual examinations, etc., the 
RIN holder stamps the month and year of the test and its RIN on the 
cylinder. This marking is normally accomplished with steel stamps. 
However, RSPA has granted exemptions, such as E-11372, authorizing 
certain fire extinguishers and fiber-wrapped cylinders to display the 
requalification markings using labels. RSPA is considering whether to 
incorporate new marking methods for DOT specification cylinders 
following the requalification process.
    RSPA requests comments on the feasibility, costs and benefits of 
alternative marking methods, and whether affected persons believe there 
is justification for RSPA to adopt alternative methods.

Section 180.215

    This section contains the reporting and record retention 
requirements currently prescribed in Sec. 173.34(e)(8), with certain 
revisions.
    The retester authorization record requirements in current 
Sec. 173.34(e)(8)(i) would be revised to include all cylinder 
requalifiers who inspect, test, repair, or rebuild cylinders. In 
addition, proposed paragraph (d)(1) requires that records covering any 
work involving welding or brazing repairs, or the building or reheat 
treatment of cylinders must be retained by the cylinder requalifier for 
15 years. The requalifier would be required to retain inspection and 
test records until expiration of the inspection or requalification 
period or until the cylinder is again requalified, whichever occurs 
first. Records of any welding or brazing repair, rebuilding or reheat 
treatment would be required to be retained for 15 years.

XII. Regulatory Analyses and Notices

A. Executive Order 12866 and DOT Regulatory Policies and Procedures

    This proposed rule is considered a significant regulatory action 
under section 3(f) of Executive Order 12866 and was reviewed by the 
Office of Management and Budget. The rule is considered significant 
under the Regulatory Policies and Procedures of the Department of 
Transportation (44 FR 11034) because of public interest. A preliminary 
regulatory evaluation is available for review in the docket.

B. Regulatory Flexibility Impact

General
    The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires an 
agency to review regulations to assess their impact on small entities 
unless the agency determines that a rule is not expected to have a 
significant economic impact on a substantial number of small entities. 
RSPA is unable, at this time, to certify that this proposed rule will 
not have a significant impact on a substantial number of small 
entities. RSPA has performed an Initial Regulatory Flexibility Analysis 
(IRFA) of this proposed rule's potential impact on small entities, and 
the assessment has been placed into the public docket for this 
rulemaking. Written public comments that clarify the degree of 
potential impacts on affected small entities are requested.
IRFA Summary
    The Regulatory Flexibility Act is concerned with identifying the 
economic impact of regulatory actions on small businesses and other 
small entities. Unless alternative definitions have been established by 
the agency in consultation with the Small Business Administration, the 
definition of ``small business'' has the same meaning as under the 
Small Business Act. As RSPA has established no special definition, the 
agency employs thresholds published under criteria in 13 CFR 121.101, 
e.g., 500 employees for cylinder manufacturers (SIC 3443--Fabricated 
Plate Work (Boiler Shops) and SIC 3462 Iron and Steel Forgings).
    Need for the proposed rule. As indicated throughout the preamble to 
this proposed rule, current requirements for the manufacture, use, and 
requalification of cylinders can be traced to standards first applied 
in the early 1900's. The regulations were subsequently revised in a 
piecemeal fashion, with adjustments being made to address particular 
situations and problems on a case-by-case basis. This notice represents 
RSPA's first comprehensive review of requirements pertaining to the 
transportation of compressed gases in cylinders and spheres. This 
action is being taken to: (1) Simplify requirements for the production 
of new cylinders, (2) provide flexibility in the design, construction 
processes and permitted use of cylinders, (3) adopt advanced 
technological processes and procedures for cylinder manufacturing and 
requalification, (4) achieve an increased level of safety through 
simplification of the rules and regulations, (5) reduce the need to 
issue, and renew, exemptions

[[Page 58474]]

that permit variances from detailed specifications concerning materials 
of construction, design, and manufacturing processes, and (6) 
facilitate international commerce in the transportation of compressed 
gases.
    Objectives and legal basis for the proposed rule. The intended 
effect of this action is to reduce threats to health, safety and 
property in the transportation of hazardous materials, particularly 
flammable, toxic and other compressed gases. Federal hazardous 
materials transportation law (49 U.S.C. 5101 et seq.) directs the 
Secretary of Transportation to prescribe regulations for the safe 
transportation of hazardous materials in intrastate, interstate and 
foreign commerce. Section 5103(b) specifies that the regulations shall 
apply to persons transporting hazardous materials in commerce; causing 
hazardous materials to be transported in commerce; or manufacturing, 
fabricating, marking, maintaining, reconditioning, repairing, or 
testing a packaging or container that is represented, marked, 
certified, or sold by such persons as qualified for use in transporting 
hazardous material in commerce.
    Identification of potentially affected small entities. 1. 
Businesses likely to be most affected by this proposed rule are 
manufacturers of specification DOT-3 and DOT-4 series cylinders (SIC 
3443 and SIC 3462). Currently, RSPA estimates there are 40 
manufacturers of specification DOT-3 and DOT-4 series cylinders. Of 
that number, approximately 29 are ``small businesses'' under the Small 
Business Act.
    In the case of approximately eleven (11) manufacturers (five (5) of 
whom are small businesses) of high-pressure (specification DOT-3 
series) cylinders there should be little or no burden attributed to 
requirements contained in this proposed rule, as many of these new 
processes and technological innovations have already been adopted as 
part of their own quality management program.
    In addition to the above, there are another twenty-nine (29) 
cylinder manufacturers (twenty-four (24) of whom are small businesses) 
identified in RSPA's database of registered markings for packaging 
manufacturers, and/or holders of exemptions that authorize the 
manufacture, marking, and sale of cylinders that do not fully conform 
to specifications for the DOT-3 and DOT-4 series. Eight (8) of these 
cylinder manufacturers (including five (5) that meet the criterion of a 
small business) are members of the Compressed Gas Association (CGA), 
one of the primary initiators of petitions for rulemaking to revise the 
HMR for greater consistency with regulations of the world's leading 
industrial nations. It is RSPA's understanding that all CGA members 
support proposed revisions contained in the CGA petitions. However, 
that leaves another twenty-one (21) non-CGA-member cylinder 
manufacturers, of which RSPA assumes at least 90% (approximately 
nineteen (19)) meet the SBA criterion for a small business, that would 
be affected by the proposed rule.
    Some small entities may experience an adverse economic impact 
attributed to the proposed rule's prohibition on the manufacture of 
non-metric-marked specification DOT-3 and DOT-4 series cylinders after 
a future date (five years from the effective date of a final rule). 
Prior to that date, small entities would, at their own discretion, be 
permitted to manufacture (1) non-metric-marked cylinders only, (2) 
metric-marked cylinders only, or (3) a combination of non-metric-marked 
cylinders and metric-marked cylinders. However, after the phase-out 
date, these small entities may manufacture DOT-3 and DOT-4 cylinders 
conforming to metric-marked specifications only.
    RSPA anticipates that, upon review of these proposed requirements, 
some small entities currently producing specification DOT-3 or DOT-4 
series cylinders may determine that it is not economically feasible to 
continue this line of products. For example, RSPA estimates the average 
annual cost of the proposed requirement for an independent inspection 
agency to observe cylinder manufacturing operations and processes at 
$59,286 per facility. However, that average is calculated on the basis 
of a wide range of costs for individual facilities that produce 
specification DOT-4 series cylinders (e.g., $5,000 for an occasional 
production run to $100,000 for a manufacturer that operates a dedicated 
line). For manufacturers that produce a relatively large volume of 
these cylinders the CGA estimates the additional cost of manufacturing 
attributed to this provision will be an additional 10 cents per 
cylinder. For a completed 20-pound propane cylinder that currently 
sells for approximately $25 (retail price), RSPA expects that the added 
expense would not be prohibitively costly to the manufacturer or to the 
ultimate consumer.
    RSPA understands that the production of specification DOT-3 and 
DOT-4 cylinders by some manufacturers that are small businesses 
oftentimes is but one of a wide-range of pressure vessels, or other 
products, in the company's product line. Knowing the importance of 
specification DOT-3 and DOT-4 series cylinders to the viability of 
these small entities, is critical to RSPA's determination of whether 
this rule may have a significant economic impact on a substantial 
number of small manufacturing companies. Small entities are, therefore, 
specifically invited to provide comments on the economic impact of the 
proposed rule on their overall operations.
    2. In addition to cylinder manufacturers, there are approximately 
1,400 businesses currently engaged in the periodic requalification of 
high-pressure cylinders. Here, also, RSPA conservatively estimates that 
at least 90 percent of these requalifiers are small businesses. This 
number includes businesses that manage large fleets of cylinders, such 
as cylinders charged with propane to power forklift trucks, and for use 
by retail customers through cylinder exchange programs. Still other 
companies, generally thought to fall within SIC 7389 (business 
services, not elsewhere classified), manage fleets of cylinders used in 
(1) carbon dioxide service for carbonated soft drinks, (2) fire 
extinguisher service, and (3) compressed air/oxygen breathing equipment 
used in recreational diving operations, as well as by emergency 
services personnel, like firefighters. All of these businesses are 
currently approved to requalify cylinders through performance of the 
hydrostatic pressure test.
    The proposed rule would require each business to determine whether 
it should: (1) upgrade test equipment from the hydrostatic type to 
ultrasonic examination type to be able to service the older DOT 
specification cylinders and the new metric-marked cylinders, or (2) 
continue to maintain its currently installed hydrostatic test equipment 
and service only the older DOT specification cylinders (estimated to 
now number 300 million, a majority of which may be expected to remain 
in service well into the next century) and the proposed DOT-4M metric-
marked cylinder that have a marked test pressure of 70 bar.
    RSPA anticipates that some small entities currently performing 
requalification functions by the hydrostatic pressure test method may 
determine that investments in new ultrasonic test equipment (requiring 
an investment currently estimated at $50-$80 thousand amortized over a 
period of ten (10) years) may not be economically feasible, considering 
the comparatively small number of metric-marked cylinders (vs. the 
current size of the domestic fleet of approximately 300

[[Page 58475]]

million cylinders) that will be produced beginning perhaps as early as 
1999, and first requiring periodic requalification in 2004. Currently, 
five (5) of the eighteen (18) retester facilities currently performing 
requalification of cylinders by ultrasonic examination, rather than by 
hydrostatic pressure testing, under terms of special exemptions issued 
by RSPA are thought to meet the criterion for a small business.
    Although the ultrasonic examination method initially involves a 
large capital investment, it offers cost savings for businesses that 
own and/or use cylinders for the transportation of compressed gases. In 
addition, ultrasonic examination provides (1) substantial benefits for 
increased safety, (2) opportunities for reducing emissions of hazardous 
materials to the environment, and (3) reduced contamination of 
cylinders.
    Commenters are specifically invited to provide additional 
information with respect to this proposed requirement for ultrasonic 
testing of metric-marked cylinders and its potential impact on small 
entities. RSPA requests comments from affected small entities regarding 
the potential adverse impact this proposed rule may have on their 
cylinder requalification operations specifically, and the overall 
viability of their enterprise should they determine it would be 
economically prohibitive to continue to perform cylinder 
requalification services.
    3. Finally, there are literally hundreds of thousands of commercial 
establishments that own and use cylinders manufactured to 
specifications in the DOT-3 and DOT-4 series. Those business sectors 
include agriculture; mining; construction; manufacturing; 
transportation, communications, electric, gas and sanitary services; 
wholesale trade; retail trade; services; and many other nonclassifiable 
establishments. On the basis of a Small Business Administration 
estimate that of the 24 million businesses located in the U.S. only 
15,000 (.000625%) are large firms, RSPA concedes it is likely that over 
99% of the businesses that make use of compressed gases in DOT 
specification cylinders are small businesses. (Source: SBA Office of 
Advocacy, Small Business Answer Card 1998).
    RSPA believes the proposed rules will generally have a small 
individual, though significant in the aggregate (i.e., $10 million 
annually), positive benefit for all of these businesses by making the 
metric-marked cylinders they buy or lease acceptable for trade and use 
in worldwide commerce. In addition, those cylinders will be allowed to 
be charged with a wider range of compressed gases and other materials, 
and, in many cases, the period between periodic requalification will be 
extended by several years, thereby resulting in cost savings attributed 
to less frequent inspections. For example, in the case of a 
specification DOT-3AL aluminum cylinder, the 5 year retest cycle would 
be extended to 10 years for the specification DOT-3ALM. In time, there 
may be as many as 1 million such cylinders in carbon dioxide service 
for the carbonated beverage industry alone. A single retest of this 
fleet of cylinders over a ten-year period vs. the current five-year 
period, at an average cost of $10 per cylinder, i.e., $10 million, 
would result in aggregate savings to the cylinder owners of $1 million 
per year. In the very competitive soft-drink industry, RSPA believes 
that the cost savings would be shared broadly.
    To the extent that RSPA has failed to recognize potential impacts 
on the general universe of small entities that own or use cylinders, 
commenters are invited to identify those impacts and the magnitude of 
their affect on small entities.
    Reporting and recordkeeping requirements. This proposed rule 
contains one new requirement for reporting and recordkeeping. 
Specifically, persons who requalify cylinders by a visual inspection, 
as currently authorized by Sec. 173.34(e)(13), would, under proposed 
Sec. 180.209(g), be required to first obtain a requalification 
identification number (RIN) from RSPA's Associate Administrator for 
Hazardous Materials Safety under provisions of proposed Sec. 107.805. 
Essential elements of the application for approval include: (1) the 
name and address of the facility manager, (2) identification of the DOT 
specification/exemption cylinders that will be inspected at the 
facility, and (3) a signed and dated certification by the applicant 
that the facility will operate in compliance with applicable 
requirements of the HMR, and that the hazmat employees performing 
inspections have been properly trained, to include familiarization with 
the appropriate CGA C-6 series pamphlets concerning the conduct of 
visual inspections.
    An approval, if issued by the Associate Administrator for Hazardous 
Materials Safety, would be effective for a maximum of five years, at 
which time the approval holder would have to file a new application for 
approval. Other than the requirements for having to file an application 
for approval, and entering the four-digit RIN (in addition to the 
month, year and letter ``E'' currently required) on each cylinder 
requalified by the visual inspection method, there is no additional 
regulatory burden associated with this proposal.
    While the actual number of facilities currently operating under the 
exception provided by Sec. 173.34(e)(13) is unknown, RSPA assumes, on 
the basis of data compiled by the Bureau of the Census, that the actual 
number is not more than 6,691, of which 5,651 are retail dealers of 
bottled liquefied petroleum gases (SIC Code 5984), 968 are merchant 
wholesalers of industrial gases, except liquefied petroleum gases (SIC 
Code 5169), and 72 are entities identified as EPA-approved reclaimers 
of refrigerant gases.
    On a per facility basis, RSPA estimates the cost of this reporting 
and recordkeeping requirement would be $122.50 per five-year cycle. 
This estimate was calculated on the basis of cost data submitted by 
RSPA to the Office of Management and Budget in support of an approval 
issued by OMB (2137-0022) concerning Testing, Inspection and Marking 
Requirements for Cylinders. RSPA does not see this proposed regulatory 
requirement as inhibiting the ability of currently excepted retesters 
to continue to provide this cylinder requalification service to an 
extent that it threatens the viability of their primary business, i.e., 
the sale of compressed gases in relatively small units. RSPA 
specifically invites commenters to provide data that supports or 
refutes this estimate of the costs of compliance with the new 
requirement to obtain a retester (requalification) identification 
number and its impact on small businesses currently authorized to 
perform this requalification function without first having to obtain an 
approval from the Associate Administrator for Hazardous Materials 
Safety.
    Related Federal rules and regulations. With respect to the 
production, permitted use, and periodic requalification of cylinders 
used in the transportation in commerce of compressed gases, there are 
no related rules and regulations issued by other departments or 
agencies of the Federal government.
    Alternate proposals for small businesses. The Regulatory 
Flexibility Act directs agencies to establish exceptions and differing 
compliance standards, when possible, for small business, while still 
meeting objectives of the applicable regulatory statutes. In the case 
of manufacture, use, inspection, testing, retesting and requalification 
of DOT specification cylinders in compressed gas service, RSPA believes

[[Page 58476]]

that it is not possible to establish such differing standards and still 
accomplish the objectives of Federal hazardous materials transportation 
law (49 U.S.C. 5101-5127). RSPA further believes that the discussion in 
this NPRM as to the need for regulatory action, issues raised by many 
of the affected parties through petitions for rulemaking, applications 
for exemption, and otherwise, effectively requires RSPA to apply one 
set of requirements applicable to small and large businesses alike.
    While certain regulatory actions may affect the competitive 
situation of an industry by imposing relatively greater burdens on 
small-scale than on large-scale enterprises, RSPA does not believe that 
this will be the case with the proposed rule. The principal types of 
compliance expenditure effectively required by the proposed rule would 
be imposed on each cylinder represented through its specification 
markings as conforming to a DOT specification, whether manufactured by, 
used by, or serviced by a large or a small business. There are 
administrative efficiency advantages, and economies of scale, available 
to a large firm, but the requirements considered in this rulemaking are 
intended to assure a minimum level of safety for packagings used to 
contain hazardous materials that pose high-order risks in 
transportation. Thus, no provisions may be waived simply on the basis 
that they would be burdensome to a small business.
    At the same time, RSPA notes that the proposed rules were developed 
under the assumption that small businesses comprise an overwhelming 
majority of entities that would be compelled to comply, particularly 
regarding permitted use of cylinders and their periodic requalification 
for continued use. For that reason, in its development of the proposed 
rules, RSPA considered each requirement and determined this set 
represents the minimal requirements necessary for it to be able to 
assure an adequate level of safety in transportation.
    For example, as an accommodation to small businesses, RSPA proposes 
to (1) permit facilities to continue to use their currently installed 
hydrostatic pressure test equipment to retest non-metric marked 
specification cylinders, millions of which have been in service for 
several decades and may be expected to continue in service for many 
more decades, and (2) permit the requalification of certain metric-
marked cylinders, i.e., specification DOT-4M with a marked test 
pressure 70 bar.
Section 610 Review
    Pursuant to section 610 of the Regulatory Flexibility Act (5 U.S.C. 
Sec. 610), RSPA has conducted a review of current requirements for the 
manufacture, use, and requalification of cylinders. The purpose of this 
review was to identify regulations that have a significant economic 
impact on a substantial number of small entities and to revise those 
regulations, where appropriate. In proposing revisions to the existing 
regulations, RSPA has attempted to minimize the economic impact on 
small business entities. It has done this, in part, by proposing to 
reduce from fifteen to four the number of authorized DOT-3 and DOT-4 
series cylinder specifications, allowing greater fill limits for 
metric-marked cylinders, and extending the time between periodic 
requalification of metric-marked cylinders. Also, small business, such 
as boiler shops (SIC 3443), iron and steel forging shops (SIC 3462), 
merchant wholesalers of industrial gases, except liquefied petroleum 
gas (LPG) (SIC 5169), retail dealers of LPG (SIC 5984), and business 
services, not elsewhere classified (SIC 7389), will benefit from the 
greater safety provided by this proposed rule. RSPA encourages small 
entities to comment on the economic impact of proposals contained in 
this NPRM.
    First, RSPA examined whether there is a continuing need for its 
cylinder regulations. Based on the various characteristics of 
compressed gases (e.g., flammability and toxicity) and the associated 
risks that are involved in the transportation of gases, RSPA recognizes 
that there is a continuing need for its cylinder regulations. However, 
as discussed previously in this preamble, RSPA is in receipt of 
numerous petitions for rulemaking concerning the cylinder regulations. 
Many of these petitions propose that RSPA incorporate accepted industry 
practices and new technology (e.g., new marking methods). RSPA has 
accepted many of these petitions and is proposing to incorporate new 
technology where the new technology achieves an equivalent or higher 
level of safety (e.g., ultrasonic testing). RSPA also reviewed 
exemptions issued under 49 CFR Part 107 and has incorporated those 
exemption provisions that have achieved a proven safety record.
    In addition to the above, over the years, the regulated community 
has requested that RSPA reduce the complexity of its cylinder 
regulations. RSPA addressed these concerns by modifying the language 
used in the proposed rule, including a definition section and changing 
the organizational structure of the cylinder regulations. RSPA also 
recognizes that market conditions have changed dramatically since many 
of the existing rules were first adopted. Today, cylinders are 
manufactured, used, and transported to, from, and between entities in 
the global marketplace. In recognition of that worldwide sale and 
distribution of compressed gases in cylinders, RSPA is proposing to 
revise the HMR in a manner that is harmonious with international 
standards (e.g., metric-marked cylinders).
    RSPA is confident that the proposed rule and existing cylinder 
regulations do not duplicate or conflict with other Federal rules. In 
addition, conflicts with state or local regulations are expressly 
provided for in Federal hazardous materials transportation law (49 
U.S.C. Sec. 5125). Under this statutory authority, RSPA issues 
preemption determinations as to whether a State, political subdivision, 
or Indian tribe regulation or law, governing the transportation of 
hazardous materials, is preempted under Federal law (see 49 C.F.R. Part 
107, Subpart C).

C. Executive Orders 12612 and 13084

    This proposed rule has been analyzed in accordance with the 
principles and criteria contained in Executive Orders 12612 
(``Federalism'') and 13084 (``Consultation and Coordination with Indian 
Tribal Governments''). Because this proposed regulation would have no 
substantial direct effect on the States or the relationship, or the 
distribution of power and responsibilities, between the Federal 
Government and the States, RSPA has determined that this rule does not 
have sufficient federalism implications to warrant preparation of a 
Federalism Assessment. Because this rule would not significantly or 
uniquely affect the communities of the Indian tribal governments, the 
funding and consultation requirements of Executive Order 13084 do not 
apply.
    Federal hazardous material transportation law contains express 
preemption provisions at 49 U.S.C. 5125 that preempt State, local, and 
Indian tribe requirements if----
    (1) Complying with a requirement of the State, political 
subdivision, or Indian tribe and Federal hazardous material 
transportation law or regulations is not possible;
    (2) The requirement of the State, political subdivision, or Indian 
tribe, as applied or enforced, is an obstacle to accomplishing and 
carrying out Federal hazardous material transportation law or 
regulations; or

[[Page 58477]]

    (3) The requirement of the State, political subdivision, or Indian 
tribe concerns any of the following ``covered subjects'' and is not 
substantially the same as a provision of Federal hazardous material 
transportation law or regulations:
    (A) The designation, description, and classification of hazardous 
material;
    (B) The packing, repacking, handling, labeling, marking, and 
placarding of hazardous material;
    (C) The preparation, execution, and use of shipping documents 
related to hazardous material and requirements related to the number, 
contents, and placement of those documents;
    (D) The written notification, recording, and reporting of the 
unintentional release in transportation of hazardous material; and
    (E) The design, manufacture, fabricating, marking, maintenance, 
reconditioning, repairing, or testing of a packaging or container 
represented, marked, certified, or sold as qualified for use in 
transporting hazardous material.
    This proposed rule concerns the packing and handling of hazardous 
materials, and the design, manufacture, fabrication, marking, 
maintenance, and testing of cylinders that are marked and certified as 
qualified for use in the transportation of hazardous materials. If so 
adopted as final, this rule would preempt any State, local, or Indian 
tribe requirements concerning these subjects unless the non-Federal 
requirements are ``substantially the same'' (see 49 CFR 107.202(d)) as 
the Federal requirements.
    Federal law (49 U.S.C. 5125(b)(2)) provides that if DOT issues a 
regulation concerning any of the covered subjects, DOT must determine 
and publish in the Federal Register the effective date of Federal 
preemption. The effective date may not be earlier than the 90th day 
following the date of issuance of the final rule and not later than two 
years after the date of issuance.
    RSPA requests comments on what the effective date of the Federal 
preemption should be for the requirements in this proposed rule that 
concern covered subjects.

D. Unfunded Mandates Reform Act of 1995

    This proposed rule would not impose unfunded mandates under the 
Unfunded Mandates Reform Act of 1995. It does not result in costs of 
$100 million or more, in the aggregate, to any of the following: State, 
local, or Indian tribal governments, or the private sector. This rule 
is the least burdensome alternative that achieves the objective of the 
rule.

E. Paperwork Reduction Act

    Under regulations implementing the Paperwork Reduction Act of 1995, 
`` * * * an agency may not conduct or sponsor, and a person is not 
required to respond to a collection of information unless it displays a 
valid OMB control number.'' 5 CFR 1320.8(b)(iii)(6).
    The information collection and recordkeeping requirements in 
current Secs. 173.34, 173.302(c) and 178.35 pertaining to records 
prepared by persons performing the requalification, repair, rebuild and 
use of cylinders and requirements in current Sec. 173.34 pertaining to 
persons seeking approval to requalify cylinders, were approved by the 
Office of Management and Budget (OMB) under the provisions of 44 U.S.C. 
chapter 35 and assigned control number 2137-0022, with an expiration 
date of August 31, 1999. This information is used to verify that 
cylinders meet the required manufacturing standards prior to being 
authorized for initial use, and that once manufactured, the cylinders 
are maintained and used in compliance with applicable requirements of 
the HMR as packagings for hazardous materials. In this proposed rule, 
these information collection and recordkeeping requirements for records 
are revised and are in Secs. 178.35, 178.69(e)(13), 180.205, 180.209, 
180.211, 180.213, and 180.215.
    The information and recordkeeping requirements in current 
Secs. 173.300a and 173.300b for persons seeking approval to be an 
independent inspection agency, and for chemical analyses and tests of 
DOT specification and exemption cylinders conducted outside of the 
United States, were approved by OMB and assigned control number 2137-
0557, with an expiration date of July 31, 1999. The information is used 
to evaluate an applicant's qualification to perform the applicable 
packaging functions and to ensure material of construction used in 
cylinders made outside the United States are in accordance with the 
applicable requirements. In this proposed rule, the information 
collection and recordkeeping requirements are in Secs. 107.803, 
107.805, 107.807 and 180.205(c). The information collection and 
recordkeeping requirements for persons seeking approval as cylinder 
requalifiers and approval to change a cylinder's service pressure are 
removed from OMB control number 2137-0022 and being placed with the 
other approval requirements under OMB control number 2137-0557. OMB 
control number 2137-0557 includes information and recordkeeping 
requirements for other than cylinders. The estimates contained in this 
proposed rule address only the cylinder provisions.
    Because this proposed rule would establish certain new cylinder 
specifications, broaden the approval requirements for affected persons 
who requalify cylinders, and would relocate the cylinder 
requalification requirements to other sections, revisions would be made 
to the current burden hour submission. RSPA has revised the burden 
estimates based on the proposal in this NPRM and will submit revised 
burden estimates to OMB.
OMB Control Number 2137-0022
    Affected Public: Cylinder requalifiers, repairers and rebuilders, 
and owners of certain DOT specification and exemption cylinders.
    Annual Reporting and Recordkeeping Burden: 
    Number of Respondents: 500.
    Total Annual Responses: 5,000.
    Total Annual Burden Hours: 1,729.
    Total Annual Cost for Development and Maintenance: $42,683.
OMB Control Number 2137-0557
    Affected Public: Cylinder manufacturers, requalifiers, and persons 
seeking to change a cylinder's service pressure.
    Annual Reporting and Recordkeeping Burden:
    Number of Respondents: 2,027.
    Total Annual Responses: 2,027.
    Total Annual Burden Hours: 2,628.
    Total Annual Cost for Development and Maintenance: $294,544.
    RSPA invites comments on these revised information collection 
estimates, including any paperwork burdens not already considered. 
Requests for a copy of these information collections should be directed 
to Deborah Boothe, Office of Hazardous Materials Standards, Room 8102, 
400 Seventh Street, SW, Washington, DC 20590-0001. Telephone (202) 366-
8553 or 1-800-467-4922. Written comments should be received by the 
close of the comment period indentified in the DATES section of this 
rulemaking and should be addressed to the Dockets Management System as 
identified in the ADDRESSES section of this rulemaking. Comments must 
reference the docket number, RSPA 98-3684 (HM-220).

F. Regulation Identifier Number (RIN)

    A regulation identifier number (RIN) is assigned to each regulatory 
action listed in the Unified Agenda of Federal Regulations. The 
Regulatory Information Service Center publishes the Unified Agenda in 
April and October of each year. The RIN contained in the heading

[[Page 58478]]

of this document can be used to cross-reference this action with the 
Unified Agenda.

List of Subjects

49 CFR Part 107

    Administrative practice and procedure, Hazardous materials 
transportation, Packaging and containers, Penalties, Reporting and 
recordkeeping requirements.

49 CFR Part 171

    Exports, Hazardous materials transportation, Hazardous waste, 
Imports, Incorporation by reference, Reporting and recordkeeping 
requirements.

49 CFR Part 172

    Hazardous materials transportation, Hazardous waste, Labeling, 
Packaging and containers, Reporting and recordkeeping requirements.

49 CFR Part 173

    Hazardous materials transportation, Packaging and containers, 
Radioactive materials, Reporting and recordkeeping requirements, 
Uranium.

49 CFR Part 177

    Hazardous materials transportation, Motor vehicle safety, Packaging 
and containers, Reporting and recordkeeping requirements.

49 CFR Part 178

    Hazardous materials transportation, Packaging and containers, 
Reporting and recordkeeping requirements.

49 CFR Part 180

    Hazardous materials transportation, Motor vehicle safety, Packaging 
and containers, Reporting and recordkeeping requirements.
    In consideration of the foregoing, title 49, Chapter I, Subchapters 
A and C of the Code of Federal Regulations, are proposed to be amended 
as follows:

PART 107--HAZARDOUS MATERIALS PROGRAM PROCEDURES

    1. The authority citation for Part 107 would continue to read as 
follows:

    Authority: 49 U.S.C. 5101-5127, 44701; Sec. 212-213, Pub. L. 
104-121, 110 Stat. 857; 49 CFR 1.45, 1.53.

Sec. 107.3  [Amended]

    2. In Sec. 107.3, the definition of ``Registration'' would be 
amended by removing the wording ``registration with RSPA as a cylinder 
retester pursuant to 49 CFR 173.34(e)(1), or''.
    3. Subpart I would be added to Part 107 to read as follows:

Subpart I--Approval of Independent Inspection Agencies, Cylinder 
Requalifiers, and Non-domestic Chemical Analyses and Tests of DOT 
Specification Cylinders

Sec.
107.801  Purpose and Scope.
107.803  Approval of independent inspection agency.
107.805  Approval of cylinder requalifiers.
107.807  Approval of non-domestic chemical analyses and tests.

Subpart I--Approval of Independent Inspection Agencies, Cylinder 
Requalifiers, and Non-domestic Chemical Analyses and Tests of DOT 
Specification Cylinders


Sec. 107.801  Purpose and scope.

    (a) This subpart prescribes procedures for--
    (1) A person who seeks approval to be an independent inspection 
agency to perform cylinder inspections and verifications required by 
parts 178 and 180 of this chapter;
    (2) A person who seeks approval to engage in the requalification 
(i.e., inspection, testing or certification), rebuild or repair of a 
cylinder manufactured in accordance with a DOT specification under 
subchapter C of this chapter or under the terms of an exemption issued 
under this part;
    (3) A person who seeks approval to perform the manufacturing 
chemical analyses and tests of DOT specification or exemption cylinders 
outside the United States.
    (b) No person may engage in a function identified in paragraph (a) 
of this section unless approved by the Associate Administrator in 
accordance with the provisions of this subpart. Each person shall 
comply with the applicable requirements in this subpart. In addition, 
the procedural requirements in subpart H of this part apply to the 
filing, processing and termination of an approval issued under this 
subpart.


Sec. 107.803  Approval of independent inspection agency.

    (a) General. Prior to performing cylinder inspections and 
verifications required by parts 178 and 180 of this chapter, a person 
must apply to the Associate Administrator for an approval as an 
independent inspection agency. A person approved as an independent 
inspection agency is not a RSPA agent or representative.
    (b) Criteria. No applicant for approval as an independent 
inspection agency may be engaged in the manufacture of cylinders for 
use in the transportation of hazardous materials, or be directly or 
indirectly controlled by, or have a financial involvement with, any 
entity that manufactures cylinders for use in the transportation of 
hazardous materials, except for providing services as an independent 
inspector.
    (c) Application information. Each applicant must submit an 
application in conformance with Sec. 107.705 that must contain the 
information prescribed in Sec. 107.705(a). In addition, the application 
must contain the following information:
    (1) Name and address of each manufacturing facility where tests and 
inspections are to be performed and a detailed description of the 
inspection and testing facilities to be used by the applicant and the 
applicant's ability to perform the inspections and to verify the 
inspections required by part 178 of this chapter or under the terms of 
an exemption issued under this part.
    (2) Name, address, and principal business activity of each person 
having any direct or indirect ownership interest in the applicant 
greater than three percent and any direct or indirect ownership 
interest in each subsidiary or division of the applicant.
    (3) Name of each individual whom the applicant proposes to employ 
as an inspector and will be responsible for certifying inspection and 
test results and a statement of that person's qualifications.
    (4) An identification or qualification number assigned to each 
inspector who is supervised by a certifying inspector identified in 
(c)(3) of this section.
    (5) A statement that the applicant will perform its functions 
independent of the manufacturers and owners of the cylinders.
    (6) If the applicant's principal place of business is in a country 
other than the United States--
    (i) A copy of the designation from the Competent Authority of that 
country delegating to the applicant an approval or designated agency 
authority for the type of packaging for which a DOT designation is 
sought; and
    (ii) A statement from the Competent Authority of that country 
stating that similar authority is delegated to other Independent 
Inspection Agencies who are approved under this subpart and that no 
condition or limitation will be imposed upon United States citizens or 
organizations that is not required of its own citizenry.
    (7) The date and signature of the person certifying the approval 
application
    (d) Facility inspection. Upon the request of the Associate 
Administrator, the applicant shall allow the Associate Administrator or 
the Associate Administrator's designee to inspect the applicant's 
facilities and records. The person seeking approval must bear the cost 
of RSPA's inspection.

[[Page 58479]]

Sec. 107.805  Approval of cylinder requalifiers.

    (a) General. A person must meet the requirements of this section to 
be approved to inspect, test, certify, repair, or rebuild a cylinder in 
accordance with a DOT specification under subpart C of part 178 or 
subpart C of part 180 of this chapter or under the terms of an 
exemption issued under this part.
    (b) Each applicant must arrange for an independent inspection 
agency, approved by the Associate Administrator pursuant to this 
subpart, to perform a review of its inspection or requalification 
operation. The person seeking approval must bear the cost of the 
inspection. A list of approved independent inspection agencies is 
available from the Associate Administrator at the address listed in 
Sec. 107.705. Assistance in obtaining an approval may be requested from 
the same address.
    (c) Application for approval. If the inspection performed by an 
independent inspection agency is completed with satisfactory results, 
the applicant must submit a letter of recommendation from the 
independent inspection agency, an inspection report, and an application 
that must contain the information prescribed in Sec. 107.705(a). In 
addition, the application must contain the following information: the 
name of the facility manager; the DOT specification/exemption cylinders 
that will be inspected, tested, repaired, or rebuilt at the facility; a 
certification that the facility will operate in compliance with the 
applicable requirements of subchapter C of this chapter; and the date 
and the signature of the person making the certification.
    (d) Issuance of requalifier identification number (RIN). The 
Associate Administrator issues a RIN as evidence of approval to 
requalify DOT specification/exemption cylinders if it is determined, 
based on the applicant's submission and other available information, 
that the applicant's qualifications and, when applicable, facility are 
adequate to perform the requested functions in accordance with the 
criteria prescribed in subpart C of part 180 of this chapter.
    (e) Expiration of RIN. Unless otherwise provided in the issuance 
letter, an approval expires five years from the date of issuance, 
provided that the applicant's facility and qualifications are 
maintained at or above the level observed at the time of inspection by 
the independent inspection agency, or at the date of the certification 
in the application for approval, for facilities only performing 
inspections made under Sec. 180.209(g) of this chapter.
    (f) Exceptions. Notwithstanding requirements in paragraphs (b) and 
(c) of this section, a person who only performs inspections in 
accordance with Sec. 180.209(g) of this chapter must submit a request 
which, in addition to the information prescribed in Sec. 107.705(a) 
contains; the facility manager for each location in which 
requalifications would be performed; the DOT specification/exemption 
cylinders that will be inspected at the facility; a certification that 
the facility will operate in compliance with the applicable 
requirements of subchapter C of this chapter; a certification that the 
persons performing inspections have been trained and have the 
information contained in each applicable CGA pamphlet incorporated by 
reference in Sec. 171.7 of this chapter that applies to the 
requalifiers activities; and the date and the signature of the person 
making the certification. Each person shall comply with the applicable 
requirements in this subpart. In addition, the procedural requirements 
in subpart H of this part apply to the filing, processing and 
termination of an approval issued under this subpart.


Sec. 107.807  Approval of non-domestic chemical analyses and tests.

    (a) General. A person who seeks to manufacture DOT specification or 
exemption cylinders outside the United States must seek an approval 
from the Associate Administrator to perform the chemical analyses and 
tests of those cylinders outside the United States.
    (b) Application for approval. Each applicant must submit an 
application that must contain the information prescribed in 
Sec. 107.705(a). In addition, the application must contain the 
following information: the name, address and a description of each 
facility at which cylinders are to be manufactured and chemical 
analyses and tests are to be performed; complete details concerning the 
dimension, materials of construction, wall thickness, water capacity, 
shape, type of joints, location and size of openings and other 
pertinent physical characteristics of each specification or exemption 
cylinder for which approval is being requested, including calculations 
for cylinder wall stress and wall thickness which may be shown on a 
drawing or on separate sheets attached to a descriptive drawing; the 
name of the independent inspection agency to be used; and the date and 
the signature of the person making the certification.
    (c) Facility inspections. Upon the request of the Associate 
Administrator, the applicant shall allow the Associate Administrator 
for HMS or the Associate Administrator's designee to inspect the 
applicant's cylinder manufacturing and testing facilities and records, 
and must provide such materials and cylinders for analyses and tests as 
the Associate Administrator may specify. The applicant or holder shall 
bear the cost of the initial and subsequent inspections, analyses, and 
tests.

PART 171--GENERAL INFORMATION, REGULATIONS, AND DEFINITIONS

    4. The authority citation for part 171 would continue to read as 
follows:

    Authority: 49 U.S.C. 5101-5127; 49 CFR 1.53.

Sec. 171.2  [Amended]

    5. In Sec. 171.2, paragraph (d)(3) would be amended by removing the 
wording ``retest or exemption markings'' and adding in its place the 
wording ``retest, exemption or requalification identification number 
(RIN) markings''.
    6. In Sec. 171.7, in the table in paragraph (a)(3), new entries 
would be added in alphanumeric sequence to read as follows:


Sec. 171.7  Reference material.

    (a) * * *
    (3) Table of material incorporated by reference. * * *

------------------------------------------------------------------------
         Source and name of material                49 CFR reference
------------------------------------------------------------------------
*                  *                  *                  *
                  *                  *                  *
American Society for Nondestructive Testing,
 PO Box 28518, 1711 Arlingate Lane, Columbus,
 OH 43228-0518
    ASNT Recommended Practice SNT-TC-1A, 1992  Part 178, subpart C,
                                                Appendix B.
*                  *                  *                  *
                  *                  *                  *
American Society for Testing and Materials

[[Page 58480]]

*                  *                  *                  *
                  *                  *                  *
    ASTM B 221-96 Standard Specification for   178.46(a)(4), Table 2.
     Aluminum and Aluminum-Alloy Extruded
     Bars, Rods, Wire, Profiles, and Tubes.
    ASTM B 221M-96 Standard Specification for  Part 178, Subpart C,
     Aluminum and Aluminum-Alloy Extruded       Appendix A, Table 2,
     Bars, Rods, Wire, Profiles, and Tubes.     Aluminum.
*                  *                  *                  *
                  *                  *                  *
    ASTM E 10-96 Standard Test Method for      178.69.
     Brinell Hardness of Metallic Materials.
    ASTM E 18-94 Standard Test Methods for     178.70.
     Rockwell Hardness and Rockwell
     Superficial Hardness of Metallic
     Materials.
*                  *                  *                  *
                  *                  *                  *
    ASTM E 165-95 Standard Test Method for     178.69.
     Liquid Penetrant Examination.
    ASTM E 213-93 Standard Practice for        178.71; 178.72; 178.73;
     Ultrasonic Examination of Metal Pipe and   Part 178, Subpart C,
     Tubing.                                    Appendix B; 180.215.
*                  *                  *                  *
                  *                  *                  *
    ASTM E 399-90e1 Standard Test Method for   178.73.
     Plane-Strain Fracture Toughness of
     Metallic Materials.
*                  *                  *                  *
                  *                  *                  *
    ASTM E 709-95 Standard Guide for Magnetic  178.69.
     Particle Examination.
    ASTM E 797-95 Standard Practice for        Part 178, Subpart C,
     Measuring Thickness by Manual Ultrasonic   Appendix B; 180.215.
     Pulse-Echo Straight-Beam Method.
*                  *                  *                  *
                  *                  *                  *
Compressed Gas Association, Inc.
*                  *                  *                  *
                  *                  *                  *
    CGA Pamphlet C-1, Methods for Hydrostatic  178.69; 178.81; 180.205.
     Testing of Compressed Gas Cylinders,
     1996.
*                  *                  *                  *
                  *                  *                  *
    CGA Pamphlet P-20, Standard for the        173.115.
     Classification of Toxic Gas Mixtures,
     1995.
*                  *                  *                  *
                  *                  *                  *
    CGA Pamphlet S-7, Method for Selecting     173.301.
     Pressure Relief Devices for Compressed
     Gas Mixtures in Cylinders, 1996.
*                  *                  *                  *
                  *                  *                  *
------------------------------------------------------------------------

Sec. 171.7  [Amended]

    7. In addition, in Sec. 171.7, in the table in paragraph (a)(3), 
the following changes would be made:
    a. In the entry ASTM A240/A240M-94b, the wording ``A240M-94b'' 
would be revised to read ``A240M-96a.''
    b. The entry ASTM A 388-67 would be removed.
    c. In the entry ASTM B 557-84, in column 2, the reference 
``178.69;'' would be added, in numeric order.
    d. In the entry ASTM E 8-89, the wording ``E 8-89'' would be 
revised to read ``E 8-96a'' and in column 2, the references ``178.36; 
178.37; 178.38; 178.39;'', ``178.45;'', ``178.50; 178.51;'', 
``178.55;'', ``178.61;'', and ``178.68;'' would be removed and 
``178.69;'' would be added, in numerical order.
    e. In the entry ASTM E 23-60, in column 1, the wording ``E 23-60'' 
would be revised to read ``E 23-96'' and in column 2, the reference 
``178.69;'' would be added, in numeric order.
    f. In the entry ASTM E 112-88, the wording ``E 112-88'' would be 
revised to read ``E 112-96'' and in column 2, the reference ``;178.69'' 
would be added, in numeric order.
    g. In the entry ASTM E 290-92, in column 2, the references 
``;178.69; 178.72'' would be added, in numeric order.
    h. In the entry CGA Pamphlet C-3, the year ``1975'' would be 
revised to read ``1994'' and in column 2, the references ``178.50; 
178.51;'', ``178.54;'', ``178.61;'', ``178.68'' would be removed and 
``178.69;'', ``178.81;'', ``180.211'' would be added, in numeric order.
    i. In the entry CGA Pamphlet C-5, in column 2, the reference 
``173.302'' would be removed and ``173.302a'' would be added, in its 
place.
    j. In the entry CGA Pamphlet C-6, in column 2, the reference 
``173.34; 180.519'' would be removed and the references ``173.198; 
180.205; 180.209; 180.211.'' would be added, in its place.
    k. In the entry CGA Pamphlet C-6.1, in column 2, the reference 
``173.34'' would be removed and the references ``180.205; 180.209'' 
would be added, in its place.
    l. In the entry CGA Pamphlet C-6.2, in column 2, the reference 
``173.34'' would be removed and the reference ``180.205'' would be 
added, in its place.
    m. In the entry CGA Pamphlet C-6.3, in column 2, the reference 
``173.34'' would be removed and the references ``180.205; 180.209'' 
would be added, in its place.
    n. In the entry CGA Pamphlet C-8, in column 2, the reference 
``173.34'' would be removed and the reference ``180.205'' would be 
added, in its place.
    o. In the entry CGA Pamphlet C-11, in column 2, the reference 
``178.35'' would be removed and the references ``178.35; 178.69'' would 
be added, in its place.
    p. In the entry CGA Pamphlet C-12, in column 2, the reference 
``173.34;'' would be removed and the references 173.301;'' and 
``;180.205'' would be added, in numeric order.
    q. In the entry CGA Pamphlet C-13, in column 2, the reference 
``173.34;'' would be removed and the references ``; 180.205;'', and 
``180.209.'' would be added, in numeric order.
    r. In the entry CGA Pamphlet C-14, in column 2, the reference 
``173.34'' would

[[Page 58481]]

be removed and the reference ``173.301'' would be added, in its place.
    s. In the entry CGA Pamphlet S-1.1, in column 2, the reference 
``173.34'' would be removed and the references ``173.301; 173.304a.'' 
would be added, in its place.
    8. In Sec. 171.8, definitions for ``Metric-marked cylinder'' and 
``Nonmetric-marked cylinder'' would be added, in alphabetical order, to 
read as follows:


Sec. 171.8  Definitions and abbreviations.

* * * * *
    Metric-marked cylinder means a cylinder manufactured to the DOT 3M, 
3ALM, 3FM or 4M specification prescribed in Secs. 178.69 through 178.81 
of this subchapter.
* * * * *
    Nonmetric-marked cylinder means a cylinder manufactured to a DOT 
specification prescribed in Secs. 178.35 through 178.68 of this 
subchapter that was in effect on [DATE PRIOR TO EFFECTIVE DATE OF THE 
FINAL RULE].
* * * * *


Sec. 171.8  [Amended]

    9. In addition, in Sec. 171.8, in the definition of ``Filling 
density'', paragraph (1) would be amended by revising the reference 
``Sec. 173.304(a)(2)Table Note 1'' to read ``Sec. 173.304a(a)(2) Table 
Note 1''.
    10. In Sec. 171.12, paragraph (b)(15) would be revised to read as 
follows:


Sec. 171.12  Import and export shipments.

* * * * *
    (b) * * *
    (15) Cylinders not manufactured to a DOT specification must conform 
to the requirements of Sec. 173.301(j) through (l) of this subchapter 
or, for Canadian manufactured cylinders, to the requirements of 
Sec. 171.12a(b)(13).
* * * * *
    11. In Sec. 171.12a, in paragraph (b)(13) a new sentence would be 
added at the end of the paragraph, and paragraphs (b)(13)(i) through 
(b)(13)(v) would be added to read as follows:


Sec. 171.12a  Canadian shipments and packagings.

* * * * *
    (b) * * *
    (13) * * * However, a cylinder made in Canada that meets the 
following conditions is authorized for the transportation of a 
hazardous material within the United States:
    (i) The cylinder was manufactured on or after January 1, 1977;
    (ii) During the manufacturing process, the cylinder was marked with 
an approval number and an inspector's mark authorized by TDG or by its 
predecessor, the Railway Transport Committee of the Canadian Transport 
Commission (CTC), in its regulations for the Transport of Dangerous 
Commodities by Rail and was marked ``CTC'' or ``TDG'';
    (iii) The cylinder is in full conformance with the specifications 
prescribed by the TDG regulations;
    (iv) The cylinder has been requalified under a program authorized 
by the Canadian regulations or requalified in accordance with subpart C 
of part 180 of this subchapter within the prescribed requalification 
period; and
    (v) At the time the requalification is performed, in addition to 
the markings prescribed in Sec. 180.211 of this subchapter, the 
cylinder is marked ``DOT/'' immediately before the Canadian 
specification marking.
* * * * *

PART 172--HAZARDOUS MATERIALS TABLE, SPECIAL PROVISIONS, HAZARDOUS 
MATERIALS COMMUNICATIONS, EMERGENCY RESPONSE INFORMATION, AND 
TRAINING REQUIREMENTS

    12. The authority citation for Part 172 would continue to read as 
follows:

    Authority: 49 U.S.C. 5101-5127; 49 CFR 1.53.

Sec. 172.101  [Amended]

    13. Section 172.101, in the Hazardous Materials Table, the 
following changes would be made:
    a. For the entry ``Cyanogen'', in Column (8b), the reference 
``192'' would be removed and ``304'' would be added in its place.
    b. For the entry ``Germane'', in Column (8b), the reference ``192'' 
would be removed and ``302'' would be added in its place.
    c. For the entry ``Iron pentacarbonyl'', in Column (8b), the 
reference ``192'' would be removed and ``226'' would be added in its 
place.

PART 173--SHIPPERS--GENERAL REQUIREMENTS FOR SHIPMENTS AND 
PACKAGINGS

    14. The authority citation for Part 173 would continue to read as 
follows:

    Authority: 49 U.S.C. 5101-5127, 44701; 49 CFR 1.45, 1.53.

Sec. 173.34  [Removed]

    15. Section 173.34 would be removed.
    16. Section 173.40 would be revised to read as follows:


Sec. 173.40  General packaging requirements for toxic materials 
packaged in cylinders.

    When this section is referenced for a hazardous material elsewhere 
in this subchapter, the following requirements are applicable to 
cylinders used for that material:
    (a) Authorized cylinders. A cylinder must conform to one of the 
specifications for cylinders in subpart C of part 178 of this 
subchapter, except that Specification 8, 8AL, and 39 cylinders are not 
authorized. After [EFFECTIVE DATE OF THE FINAL RULE] DOT 3AL cylinders 
made of aluminum alloy 6351 may not be filled and offered for 
transportation or transported with a Division 2.3, Zone A or B 
material, a Division 6.1, Zone A or B material or any liquid that meets 
the definition of Division 6.1 and meets criteria for Packing Group I, 
Hazard Zones A or B, as specified in Sec. 173.133.
    (b) Closures. Each cylinder containing a Hazard Zone A material 
must be closed with a plug or valve conforming to the following:
    (1) Each plug or valve must have a taper-threaded connection 
directly to the cylinder and be capable of withstanding the test 
pressure of the cylinder;
    (2) Each valve must be of the packless type with non-perforated 
diaphragm, except that for corrosive materials, a valve may be of the 
packed type provided the assembly is made gas-tight by means of a seal 
cap with gasketed joint attached to the valve body or the cylinder to 
prevent loss of material through or past the packing;
    (3) Each valve outlet must be sealed by a threaded cap or threaded 
solid plug; and
    (4) Cylinder, valves, plugs, outlet caps, luting and gaskets must 
be compatible with each other and with the lading.
    (c) Additional handling protection. Each cylinder or cylinder 
overpack combination offered for transportation containing a Division 
2.3 or 6.1 Hazard Zone A or B material must meet the puncture 
resistance and valve damage protection performance requirements of this 
section. In addition to the requirements of this section, overpacks 
must conform to the overpack provisions of Sec. 173.25.
    (1) Puncture resistance. Each cylinder or cylinder overpack 
combination must be qualified under the puncture resistance test 
specified in Sec. 178.69(h)(3) of this subchapter. However, a cylinder 
meeting the conditions in the following table is excepted from the 
puncture resistance test requirements of this section and of 
Sec. 178.69(h)(3) of this subchapter:

[[Page 58482]]



------------------------------------------------------------------------
                                                     Maximum
                                                      water     Minimum
                                                      filled      wall
            DOT specification/material                gross    thickness
                                                      weight     (inch)
                                                      (lbs.)
------------------------------------------------------------------------
3A................................................        215      0.180
3AA...............................................        255      0.220
------------------------------------------------------------------------

    (2) Valve damage protection. Each cylinder with a valve must be 
equipped with a protective cap, other valve protection device or an 
overpack sufficient to protect the valve from deformation, breakage or 
leakage resulting from a drop of 2.0 m (7 ft) onto a non-yielding 
surface. Impact must be at an orientation most likely to cause damage.
    (d) Interconnection. Cylinders may not be manifolded or 
interconnected.


Sec. 173.115  [Amended]

    17. In Sec. 173.115, in paragraph (c)(2), in the last sentence, the 
wording ``or CGA Pamphlet P-20'' is added immediately following the 
word ``subpart''.
    18. In Sec. 173.115, in paragraph (j), the reference 
``Sec. 173.304(a)(2)'' would be revised to read 
``Sec. 173.304a(a)(2)''.
    19. Section 173.163 would be revised to read as follows:


Sec. 173.163  Hydrogen fluoride.

    Hydrogen fluoride (hydrofluoric acid, anhydrous) must be packaged 
in specification 3, 3A, 3AA, 3B, 3BN, 3E, 4A, or 3M cylinders; or 
Specification 4B, 4BA, 4BW, or 4M cylinders, if they are not brazed. 
Filling density may not exceed 85 percent of the cylinder's water 
weight capacity. Metric-marked cylinders must be requalified by 
ultrasonic examination in accordance with Sec. 180.207 of this 
subchapter. Nonmetric-marked cylinders must be requalified by 
ultrasonic examination in accordance with Sec. 180.209(a)(2) of this 
subchapter.
    20. Section 173.192 would be revised to read as follows:


Sec. 173.192  Packaging for certain toxic gases in Hazard Zone A.

    When Sec. 172.101 of this subchapter specifies that a toxic 
material be packaged under this section, only specification cylinders 
are authorized, as follows:
    (a) Specification 3A1800, 3AA1800, 3AL1800, or 3E1800 cylinders; 
3M, 3ALM, or 3FM cylinders with a marked test pressure of 200 bar (2900 
psig); under the following conditions:
    (1) Specification 3A, 3AA, 3AL, 3M, 3ALM, or 3FM cylinders may not 
exceed 57 kg (125 pounds) water capacity (nominal).
    (2) Specification 3AL or 3ALM cylinders may only be offered for 
transportation or transported by highway and rail.
    (b) Packagings must conform to the requirements of Sec. 173.40.
    (c) For cylinders used for phosgene:
    (1) The filling density may not exceed 125 percent;
    (2) A cylinder may not contain more than 68 kg (150 pounds) of 
phosgene; and
    (3) Each cylinder containing phosgene must be tested for leakage 
before it is offered for transportation or transported and must show no 
leakage; this test must consist of immersing the cylinder and valve, 
without the protection cap attached, in a bath of water at a 
temperature of approximately 66'C (150'F) for at least 30 minutes, 
during which time frequent examinations must be made to note any escape 
of gas. The valve of the cylinder must not be loosened after this test. 
Alternatively, each cylinder containing phosgene may be tested for 
leakage by a method approved in writing by the Associate Administrator 
for Hazardous Materials Safety.


Sec. 173.198  [Amended]

    21. In Sec. 173.198, in paragraph (a), the reference 
``Sec. 173.34(e)'' would be revised to read ``Sec. 180.205 of this 
subchapter''.
    22. In Sec. 173.226, paragraph (a) would be revised to read as 
follows:


Sec. 173.226  Materials poisonous by inhalation, Division 6.1, Packing 
Group I, Hazard Zone A.

* * * * *
    (a) In seamless specification cylinders conforming to the 
requirements of Sec. 173.40.
* * * * *
    23. In Sec. 173.227, paragraph (a) would be revised to read as 
follows:


Sec. 173.227  Materials poisonous by inhalation, Division 6.1, Packing 
Group I, Hazard Zone B.

* * * * *
    (a) In packagings as authorized in Sec. 173.226 and seamless and 
welded specification cylinders conforming to the requirements of 
Sec. 173.40.
* * * * *
    24. Section 173.228 would be revised to read as follows:


Sec. 173.228  Bromine pentafluoride or bromine trifluoride.

    (a) The following packagings are authorized:
    (1) Specification 3A150, 3AA150, 3B240, 3BN150, 4B240, 4BA240, 
4BW240 and 3E1800 cylinders;
    (2) Specification 3M, 3ALM, 3FM, and 4M cylinders with a minimum 
marked test pressure of 25 bar (363 psig).
    (b) Material in Hazard Zones A and B must be transported in 
cylinders conforming to the requirements of Sec. 173.40, except that 
material in Hazard Zone A must be transported only in seamless 
specification cylinders.
    (c) Cylinder valves must be protected as specified in 
Sec. 173.301(h). No cylinder may be equipped with any pressure relief 
device.


Secs. 173.300a, 173.300b, 173.300c  [Removed]

    25. In part 173, Secs. 173.300a, 173.300b, and 173.300c would be 
removed.
    26. Section 173.301 would be revised to read as follows:


Sec. 173.301  General requirements for shipment of compressed gases in 
cylinders and spherical pressure vessels.

    (a) General qualifications for use of cylinders. As used in this 
subpart, filled means an introduction or presence of a hazardous 
material in a cylinder. A Class 2 material (gas) offered for 
transportation in a cylinder must be prepared in accordance with this 
section and Secs. 173.302 through 173.305.
    (1) Compressed gases must be in metal cylinders and containers 
built in accordance with the DOT (and ICC, as shown) specifications, as 
shown in this paragraph (a)(1), in effect at the time of manufacture, 
and marked as required by the specification and the regulation for 
requalification if applicable:

Packagings

2P
2Q
ICC-3\1\
---------------------------------------------------------------------------

    \1\ Use of existing cylinders is authorized. New construction is 
not authorized after [FIVE YEARS FROM EFFECTIVE DATE OF THE FINAL 
RULE], except that new construction of ICC-3 cylinders is currently 
not authorized.
---------------------------------------------------------------------------

3A\1\
3AA\1\
3AL\1\
3ALM
3AX\1\
3A480X\1\
3AAX\1\
3B\1\
3BN\1\
3E
3FM
3HT
3M
3T\1\
4AA480
4B\1\
4B240ET\1\
4BA\1\
4BW\1\
4D
4DA

[[Page 58483]]

4DS
4E\1\
4L
4M
8
8AL
39

    (2) A cylinder must be filled in accordance with this part. Before 
each filling of a cylinder, the person filling the cylinder must 
visually inspect the outside of the cylinder. A cylinder that has a 
crack or leak, is bulged, has a defective valve or pressure relief 
device, or bears evidence of physical abuse, fire or heat damage, or 
detrimental rusting or corrosion may not be used unless it is properly 
repaired and requalified as prescribed in subpart C of part 180 of this 
subchapter.
    (3) A cylinder that has previously contained a Class 8 material 
must be requalified in accordance with Sec. 180.205(e) of this 
subchapter.
    (4) When a cylinder with a marked pressure limit is prescribed, 
another cylinder made under the same specification but with a higher 
marked pressure limit is authorized. For example, a cylinder marked 
``DOT-4B500'' may be used when ``DOT-4B300'' is specified and a 
cylinder marked ``DOT-3FM140'' may be used when ``DOT-3FM70'' is 
authorized.
    (5) No person may fill a cylinder overdue for periodic 
requalification with a hazardous material and then offer it for 
transportation. This requirement does not apply to a cylinder that was 
filled prior to the requalification due date.
    (6) After its authorized service life has expired, a cylinder may 
not be offered for transportation in commerce.
    (7) For nonmetric-marked cylinders, the pressure of the hazardous 
material at 55 deg.C (131 deg.F) must not exceed the service pressure 
of the cylinder. Sufficient outage shall be provided so that the 
cylinder will not be liquid full at 55 deg.C (131 deg.F).
    (8) Metric-marked cylinders containing permanent gases must be 
filled in accordance with Sec. 173.302b.
    (9) Metric-marked cylinders containing liquefied gases must be 
filled in accordance with Sec. 173.304b.
    (10) DOT 2P, 2Q, 3E, 3HT, spherical 4BA, 4D, 4DA, 4DS, 39, and 
spherical 4M cylinders must be shipped in strong outside packagings. 
The strong outside packaging must conform to paragraph (h) of this 
section and to Sec. 173.25.
    (b) Cylinder markings. Required markings on a cylinder must be 
legible and must meet the applicable requirements of subpart C of part 
180 of this subchapter. Additional information may be marked on the 
cylinder provided it does not affect the required markings prescribed 
in the applicable cylinder specification.
    (c) Toxic gases and mixtures. Cylinders containing toxic gases and 
toxic gas mixtures that meet the criteria of Division 2.3 Hazard Zone A 
or B must conform to the requirements of Sec. 173.40, CGA Pamphlets S-
1.1 and S-7. DOT 39 cylinders may not be used for toxic gases or toxic 
gas mixtures that meet the criteria for Division 2.3 Hazard Zone A or 
B.
    (d) Gases capable of combining chemically. A filled cylinder may 
not contain any gas or material that is capable of combining chemically 
with the cylinder's contents or with the cylinder material of 
construction so as to endanger the cylinder's serviceability. After 
[EFFECTIVE DATE OF THE FINAL RULE] DOT 3AL cylinders made of aluminum 
alloy 6351 may not be filled and offered for transportation with 
pyrophoric gases.
    (e) Ownership of cylinder. A cylinder filled with a hazardous 
materials may not be offered for transportation unless it was filled by 
the owner of the cylinder or with the owner's consent.
    (f) Pressure relief device systems. (1) Except as provided in 
paragraph (f)(6) and (f)(7) of this section, a cylinder filled with a 
gas for transportation must be equipped with one or more pressure 
relief devices sized and selected as to type, location and quantity and 
tested in accordance with CGA Pamphlets S-1.1 (compliance with 
paragraph 9.1.1.1 of CGA Pamphlet S-1.1 is not required) and S-7. A 
pressure relief device is required on a DOT 39 cylinder and a cylinder 
used for acetylene in solution, regardless of cylinder size or filled 
pressure. A DOT 39 cylinder used for liquefied Division 2.1 materials 
must be equipped with a metal pressure relief valve. Fusible pressure 
relief devices are not authorized on a DOT 39 cylinder containing a 
liquefied gas.
    (2) When installed, a pressure relief device must be in the vapor 
space of a cylinder.
    (3) For a metric-marked cylinder, the start-to-discharge pressure 
of a pressure relief device may not be less than the marked test 
pressure of the cylinder. For a nonmetric-marked DOT-3 series cylinder, 
from the first requalification due on and after [EFFECTIVE DATE OF THE 
FINAL RULE,] the start-to-discharge pressure of the pressure relief 
device, may not be less than the minimum required test pressure. To 
ensure that the relief device does not open below its set pressure, the 
allowable tolerances for all the pressure relief devices must range 
from zero to plus 10% of its setting. The pressure relief device must 
be capable of preventing rupture of the normally filled cylinder when 
subjected to a fire test conducted in accordance with CGA Pamphlet C-
14, or in the case of an acetylene cylinder, CGA Pamphlet C-12.
    (4) Before each filling of a cylinder equipped with a pressure 
relief device, the person filling the cylinder must visually inspect 
each pressure relief device for corrosion, damage, rust, plugging of 
external pressure relief device channels, and other mechanical defects 
such as extrusion of fusible metal. A cylinder with a defective 
pressure relief device may not be used.
    (5) Before a filled cylinder is offered for transportation from the 
cylinder filling facility, the pressure relief device must be tested 
for leaks. A cylinder with a leaking pressure relief device may not be 
offered for transportation.
    (6) A pressure relief device is not required on----
    (i) A cylinder 305 mm (12 inches) or less in length, exclusive of 
neck, and 114 mm (4.5 inches) or less in outside diameter, except:
    (A) When filled with a liquefied gas for which this part requires a 
service pressure of 1800 psi or higher for a nonmetric-marked cylinder, 
and a test pressure of 186 bar (2700 psi) or higher for a metric-marked 
cylinder; or
    (B) When filled with a nonliquefied gas to a pressure less than 
1800 psi for a nonmetric-marked cylinder and 124 bar for a metric-
marked cylinder.
    (ii) A cylinder with a water capacity of less than 454 kg (1000 
lbs) filled with a nonliquefied gas to a pressure of 21 bar (300 psi) 
or less at 21 deg.C (70 deg.F).
    (iii) A cylinder containing a Class 3 or a Class 8 material without 
pressurization unless otherwise specified for the hazardous material.
    (7) A pressure relief device is prohibited on a cylinder filled 
with a Division 2.3 or a Division 6.1 material in Hazard Zone A.
    (g) Manifolding cylinders in transportation. (1) Cylinder 
manifolding is only authorized under conditions prescribed in this 
paragraph (g). Manifolded cylinders shall be supported and held 
together as a unit by structurally adequate means. Except for Division 
2.2 materials, each cylinder must be equipped with an individual 
shutoff valve that must be tightly closed while in transit. Manifold 
branch lines must be sufficiently flexible to prevent damage to the 
valves which otherwise might result from the use of rigid branch lines. 
Each cylinder must be individually equipped with a pressure relief 
device as required in paragraph (f) of this section. Pressure relief 
devices

[[Page 58484]]

on manifolded cylinders, filled with a compressed gas, must be arranged 
to discharge upward and unobstructed to the open air in such a manner 
as to prevent any escaping gas from contacting personnel or any 
adjacent cylinders. Valves and pressure relief devices on manifolded 
cylinders, filled with a compressed gas, must be protected by framing 
or other method which is equivalent to the valve protection required in 
paragraph (h) of this section. Manifolding is authorized for cylinders 
containing the following gases:
    (i) Nonliquefied compressed (permanent)gases authorized by 
Sec. 173.302.
    (ii) Liquefied compressed gases that are authorized by 
Sec. 173.304. Each manifolded cylinder, containing a liquefied 
compressed gas, must be separately filled and means must be provided to 
ensure that no interchange of cylinder contents can occur during 
transportation.
    (iii) Acetylene as authorized by Sec. 173.303.
    (2) For the checking of tare weights or for replacement of solvent, 
the cylinder must be removed from the manifold. This requirement is not 
intended to prohibit the filling of acetylene cylinders while 
manifolded.
    (h) Cylinder valve protection. (1) Except for a cylinder meeting 
the following conditions, a cylinder offered for transportation must 
meet the performance requirements specified in paragraph (h)(2) of this 
section:
    (i) A cylinder manufactured before [FIVE YEARS FROM EFFECTIVE DATE 
OF THE FINAL RULE.];
    (ii) A cylinder containing only a Division 2.2 material without a 
Division 5.1 subsidiary hazard;
    (iii) A cylinder containing a Class 9 material or a Class 8 
material only corrosive to metal;
    (iv) A cylinder with a water capacity of 4.8 liters (293 cubic 
inches) or less containing oxygen, compressed;
    (v) A cylinder containing oxygen, refrigerated liquid (cryogenic 
liquid).
    (2) Each cylinder valve assembly must be of sufficient strength or 
protected such that no leakage occurs when a cylinder with the valve 
installed is dropped 1.8 m (6 ft.) or more onto a non-yielding floor, 
impacting the valve assembly or protection device at an orientation 
most likely to cause damage. The cylinder valve assembly protection may 
be provided by any method that meets the performance requirement in 
this paragraph (h)(2), examples include:
    (i) Equipping the cylinder with a securely attached metal cap.
    (ii) Packaging the cylinder in a box, crate or other strong outside 
packaging conforming to the requirements of Sec. 173.25.
    (iii) Constructing the cylinder such that the valve is recessed 
into the cylinder or otherwise protected.
    (i) Cylinders mounted on motor vehicles or in frames. Seamless DOT 
specification cylinders longer than two meters (6.5 feet) are 
authorized for transportation only when horizontally mounted on a motor 
vehicle or in an ISO framework or other framework of equivalent 
structural integrity. Cylinders may be transported by rail in container 
on freight car (COFC) or trailer on flat car (TOFC) service only under 
conditions approved by the Associate Administrator for Safety, Federal 
Railroad Administration. The cylinder must be configured as follows:
    (1) Each cylinder must be fixed at one end of the vehicle or 
framework with provision for thermal expansion at the opposite end 
attachment;
    (2) The valve and pressure relief device protective structure must 
be sufficiently strong to withstand a force equal to twice the weight 
of the cylinder and framework assembly with a safety factor of four, 
based on the ultimate strength of the material used; and
    (3) Discharge from a pressure relief device shall be arranged in 
such a manner to prevent any escaping gas from contacting personnel or 
any adjacent cylinders.
    (j) Non-specification cylinders in domestic use. Except as provided 
in paragraphs (k) and (l) of this section, a filled non-DOT 
specification cylinder, other than a DOT exemption cylinder, may not be 
offered for transportation or transported to, from, or within the 
United States.
    (k) Importation of foreign cylinders for discharge within a single 
port area. A cylinder manufactured to other than a DOT specification 
that has been certified as being in conformance with the transportation 
regulations of another country may be authorized upon written request 
to and approval by the Associate Administrator for Hazardous Materials 
Safety, for transportation within a single port area, provided--
    (1) The cylinder is transported in a closed freight container;
    (2) The cylinder is certified by the importer to provide a level of 
safety at least equal to that required by the regulations in this 
subchapter for a comparable DOT specification cylinder; and
    (3) The cylinder is not refilled for export unless in compliance 
with paragraph (l) of this section.
    (l) Charging of foreign cylinders for export. A cylinder 
manufactured outside the United States that was not manufactured, 
inspected, tested and marked in accordance with part 178 of this 
subchapter or a cylinder manufactured to other than a DOT specification 
or exemption may be filled with a gas in the United States and offered 
for transportation and transported for export, if the following 
conditions are met:
    (1) The cylinder has been requalified and marked with the month and 
year of requalification in accordance with subpart C of part 180 of 
this subchapter, or has been requalified as authorized by the Associate 
Administrator for Hazardous Materials Safety.
    (2) The maximum filling density and service pressure for each 
cylinder conform to the requirements of this part for the gas involved.
    (3) The bill of lading or other shipping paper shall identify the 
cylinder and shall carry the following certification: ``This cylinder 
has (These cylinders have) been qualified, as required, and filled in 
accordance with the DOT requirements for export.''
    (m) Sharp attachments. Attachments to cylinders filled for 
transportation may not have sharp corners, edges, or any other features 
that are capable of causing puncture or damage to other freight. 
Attachments include all permanent structural attachments, as well as 
anything temporarily attached to the cylinder, such as skids.
    27. Section 173.301a would be added to read as follows:


Sec. 173.301a  Additional general requirements for shipment of 
nonmetric-marked cylinders.

    (a) General. The requirements in this section are in addition to 
the requirements in Sec. 173.301 and apply to the shipment of gases in 
nonmetric-marked cylinders.
    (b) Authorized cylinders not marked with a service pressure. For 
authorized cylinders not marked with a service pressure, the service 
pressure is designated as follows:

------------------------------------------------------------------------
                                                               Service
                   Specification marking                       pressure
                                                                 psig
------------------------------------------------------------------------
3..........................................................         1800
3E.........................................................         1800
8..........................................................          250
------------------------------------------------------------------------

    (c) Cylinder pressure at 21 deg.C (70 deg.F). The pressure in a 
cylinder at 21 deg.C (70 deg.F) may not exceed the service pressure for 
which the cylinder is marked or designated, except as provided in 
Sec. 173.302a(b). For certain liquefied

[[Page 58485]]

gases, the pressure at 21 deg.C (70 deg.F) must be lower than the 
marked service pressure to avoid having a pressure at a temperature of 
54.4 deg.C (131 deg.F) that is greater than permitted.
    (d) Cylinder pressure at 55 deg.C (131 deg.F). The pressure in a 
cylinder at 55 deg.C (131 deg.F) may not exceed \5/4\ times the service 
pressure, except:
    (1) A cylinder filled with acetylene, liquefied nitrous oxide or 
carbon dioxide.
    (2) When a cylinder is filled in accordance with Sec. 173.302a(b), 
the pressure in the cylinder at 55 deg.C (131 deg.F) may not exceed \5/
4\ times the filling pressure.
    28. Section 173.301b would be added to read as follows:


Sec. 173.301b  Additional general requirements for shipment of metric-
marked cylinders.

    (a) Definitions. For purposes of this subpart, the following 
definitions apply to Class 2 materials in metric-marked cylinders:
    Critical temperature means the temperature above which the 
substance can not exist in the liquid state.
    Dissolved gas means a gas which is dissolved under pressure in a 
liquid phase solvent. The solvent may be supported in a porous mass.
    Filling factor of liquefied compressed gas means the mass of a gas, 
in kg (or pound), which can be filled into a 1 liter (61 cubic inches) 
water capacity container. The filling factor of each liquefied 
compressed gas must be calculated to meet all requirements of 
Sec. 173.304b.
    High pressure liquefied compressed gas means a gas which has a 
critical temperature in the range from -10  deg.C (14  deg.F) to less 
than 70  deg.C (158  deg.F).
    Low pressure liquefied compressed gas means a gas which has a 
critical temperature equal to or above 70  deg.C (158  deg.F).
    Permanent (non-liquefied compressed) gas means a gas other than in 
solution, which has a critical temperature below -10  deg.C (14 
deg.F).
    Safety factor means the ratio of the cylinder burst pressure to its 
marked test pressure. For example, a cylinder with a marked test 
pressure of 180 bar (2610 psi) and a burst pressure of 340 bar (4930 
psi) and has a safety factor of 1.89.
    Settled pressure (formerly referred to as service pressure) means 
the pressure of the contents of the cylinder at 15  deg.C (59  deg.F).
    (b) Pressure in cylinders containing a permanent gas. The pressure 
in a DOT 3M, 3FM, 3ALM or 4M cylinder containing a permanent gas must 
be as prescribed in Sec. 173.302b.
    (c) Pressure in cylinders containing a liquefied compressed gas. 
(1) The pressure in a cylinder containing a liquefied compressed gas 
which has critical temperature ranging from -10  deg.C (14  deg.F) up 
to 70  deg.C (158  deg.F) may not exceed the cylinder's marked test 
pressure or be liquid full at a temperature of 65  deg.C (149  deg.F).
    (2) The pressure in a cylinder containing a liquefied compressed 
gas which has a critical temperature greater than or equal to 70  deg.C 
(158  deg.F) may not exceed the cylinder's marked test pressure or be 
liquid full at 54  deg.C (130  deg.F).
    (d) Authorized gases for DOT 3FM cylinders. A DOT 3FM cylinder may 
only be used for gases free of corroding components with a dew point 
below -49  deg.C (-56  deg.F). A DOT 3FM cylinder is not authorized for 
hydrogen or hydrogen bearing gases (e.g., hydrogen sulfide).
    29. Section 173.302 would be revised to read as follows:


Sec. 173.302  Filling of cylinders with non-liquefied compressed gases.

    (a) General requirements. A cylinder filled with a non-liquefied 
compressed gas (except gas in solution) must be offered for 
transportation in accordance with the requirements of this section and 
Secs. 173.301, 173.301a, 173.301b, 173.302a, 173.302b and 173.305. 
Where more than one section applies to a cylinder, the most restrictive 
requirement must be followed.
    (b) Aluminum cylinders in oxygen service. Each aluminum cylinder 
filled with oxygen must meet the following conditions:
    (1) Each cylinder must be equipped only with brass or stainless 
steel valves;
    (2) Each cylinder must have only straight threads in the opening;
    (3) Each cylinder must be cleaned in accordance with the 
requirements of Federal Specification RR-C-901c, paragraphs 3.7.2, and 
3.8.2. Cleaning agents equivalent to those specified in RR-C-901c may 
be used provided they do not react with oxygen. One cylinder selected 
at random from a group of 200 or less and cleaned at the same time, 
must be tested for oil contamination in accordance with Specification 
RR-C-901c, paragraph 4.4.2.3, and meet the standard of cleanliness 
specified; and
    (4) The pressure in each cylinder may not exceed 207 bar (3000 
psig) at 21  deg.C (70  deg.F).
    (c) Each authorized cylinder containing oxygen which is 
continuously fed to tanks containing live fish may be offered for 
transportation and transported irrespective of the provisions of 
Sec. 173.24(b)(1).
    (d) Shipment of Division 2.1 materials in aluminum cylinders are 
authorized only when transported by highway, rail, or cargo-only 
aircraft.
    30. Section 173.302a would be added to read as follows:


Sec. 173.302a  Additional requirements for shipment of permanent 
(nonliquefied) compressed gases in nonmetric-marked cylinders.

    (a) Detailed filling requirements. Nonliquefied compressed gases 
(except gas in solution) for which filling requirements are not 
specifically prescribed in Sec. 173.304a must be shipped, subject to 
the requirements in this section and Secs. 173.301, 173.301a, 173.302 
and 173.305 in nonmetric-marked cylinders, as follows:
    (1) Specification 3, 3A, 3AA, 3AL, 3B, 3E, 4B, 4BA and 4BW 
cylinders.
    (2) DOT 3HT cylinders. These cylinders are authorized for aircraft 
use only and only for nonflammable gases. They have a maximum service 
life of 24 years from the date of manufacture. The cylinders must be 
equipped with pressure relief devices only of the frangible disc type 
which meet the requirements of Sec. 173.301(f). Each frangible disc 
must have a rated bursting pressure which does not exceed 90 percent of 
the minimum required test pressure of the cylinder. Discs with fusible 
metal backing are not permitted. Specification 3HT cylinders may be 
offered for transportation only when packed in strong outer packagings 
conforming to the requirements of Sec. 173.25.
    (3) For a specification 39 cylinder filled with a Division 2.1 
material, the internal volume may not exceed 75 cubic inches.
    (4) Specification 3AX, 3AAX, and 3T cylinders are authorized for 
Division 2.1 and 2.2 materials and for carbon monoxide. DOT 3T 
cylinders are not authorized for hydrogen. When used in methane 
service, the methane must be a non-liquefied gas which has a minimum 
purity of 98.0 percent methane and which is commercially free of 
corroding components.
    (5) Aluminum cylinders made to DOT specification 39 and 3AL are 
authorized for oxygen only under the conditions specified in 
Sec. 173.302(b).
    (b) Special filling limits for specification 3A, 3AX, 3AA, 3AAX, 
and 3T cylinders. A specification 3A, 3AX, 3AA, 3AAX, and 3T cylinders 
may be filled with a compressed gas, other than a liquefied, dissolved, 
Division 2.3 or 2.1 material, to a pressure 10 percent in excess of its 
marked service pressure, provided:

[[Page 58486]]

    (1) The cylinder is equipped with a frangible disc pressure relief 
devices (without fusible metal backing) having a bursting pressure not 
exceeding the minimum prescribed test pressure.
    (2) The cylinder's elastic expansion was determined at the time of 
the last test or retest by the water jacket method.
    (3) Either the average wall stress or the maximum wall stress does 
not exceed the wall stress limitation shown in the following table:

------------------------------------------------------------------------
                                                    Average     Maximum
                                                     wall        wall
                  Type of steel                     stress      stress
                                                  limitation  limitation
------------------------------------------------------------------------
Plain carbon steels over 0.35 carbon and medium
 manganese steels...............................      53,000      58,000
Steels of analysis and heat-treatment specified
 in spec. 3AA...................................      67,000      73,000
Steel of analysis and heat treatment specified
 in spec. DOT-3T................................      87,000      94,000
Plain carbon steels less than 0.35 carbon made
 prior to 1920..................................      45,000      48,000
------------------------------------------------------------------------

    (i) The average wall stress shall be computed from the elastic 
expansion data using the following formula:

S = 1.7EE / KV--0.4P

Where:

S = wall stress, pounds per square inch;
EE = elastic expansion (total less permanent) in cubic centimeters;
K = factor  x  10-7 experimentally determined for the 
particular type of cylinder being tested or derived in accordance with 
CGA Pamphlet C-5;
V = internal volume in cubic centimeter (1 cubic inch = 16.387 cubic 
centimeters);
P = test pressure, pounds per square inch.

    (ii) The maximum wall stress shall be computed from the formula:

S = (P(1.3D2 + 0.4d2)) / (D2-
d2)

Where:

S = wall stress, pounds per square inch;
P = test pressure, pounds per square inch;
D = outside diameter, inches;
d = D-2t, where t=minimum wall thickness determined by a suitable 
method.

    (iii) The formula in paragraph (b)(3)(i) of this section is derived 
from the formula in paragraph (b)(3)(ii) and the following:

EE = (PKVD2) / (D2-d2)

    (iv) Compliance with average wall stress limitation may be 
determined through computation of the elastic expansion rejection limit 
in accordance with CGA Pamphlet C-5 or through the use of the 
manufacturer's marked elastic expansion rejection limit (REE) on the 
cylinder.
    (4) That an external and internal visual examination made at the 
time of test or retest shows the cylinder to be free from excessive 
corrosion, pitting, or dangerous defects.
    (5) That a plus sign (+) be added following the test date marking 
on the cylinder to indicate compliance with paragraphs (b) (2), (3), 
and (4) of this section.
    (c) Carbon monoxide. Carbon monoxide must be offered in a 
specification 3, 3A, 3AX, 3AA, 3AAX, 3AL, 3E, or 3T cylinder having a 
minimum service pressure of 1,800 psig. The pressure in the cylinder 
may not exceed 1000 psig at 70 deg. F., except that if the gas is dry 
and sulfur free, the cylinder may be filled to five-sixths of the 
cylinder's service pressure or 2000 psig, whichever is less. A DOT 3AL 
cylinder is authorized only when transported by highway, rail or cargo-
only aircraft.
    (d) Diborane and diborane mixtures. Diborane and diborane mixed 
with compatible compressed gas must be offered in a DOT 3AA1800 
cylinder. The maximum filling density of the diborane may not exceed 7 
percent. Diborane mixed with compatible compressed gas may not have a 
pressure exceeding the service pressure of the cylinder if complete 
decomposition of the diborane occurs. Cylinder valve assembles must be 
protected in accordance with Sec. 173.301(h).
    (e) Fluorine. Fluorine must be offered in a DOT 3A1000, 3AA1000, or 
3BN400 cylinder without a pressure relief device and equipped with a 
valve protection cap. The cylinder may not be filled to over 400 psig 
at 70 deg. F. and may not contain over 6 pounds of gas.
    31. Section 173.302b would be added to read as follows:


Sec. 173.302b  Additional requirements for shipment of permanent gases 
in metric-marked cylinders.

    (a) General requirements. Permanent gases (except gas in solution) 
must be shipped, subject to this section and Secs. 173.301, and 
173.301b in a DOT specification 3ALM, 3M, 3FM or 4M cylinder.
    (1) A cylinder with a marked test pressure greater than or equal to 
35 bar (508 psi) is authorized for transportation of Division 2.1, 2.2, 
or 2.3 Hazard Zone B,C or D gas.
    (2) A DOT 3ALM, 3M, or 3FM cylinder with a marked test pressure 
greater than or equal to 200 bar (2900 psi) is authorized for 
transportation of Division 2.3 Hazard Zone A gases.
    (3) The settled pressure for a DOT 3M, 3FM or 3ALM cylinder may not 
exceed two-thirds of the cylinder's marked test pressure.
    (4) The settled pressure for a DOT 4M cylinder and a DOT 3M 
cylinder made from nickel may not exceed one-half of the cylinder's 
marked test pressure.
    (5) A DOT 3FM cylinder exceeding 454 kilogram (1000 pounds) water 
capacity is authorized for dry compressed natural gas (scrubbed to 
remove acid gases). The cylinder may not contain any liquefied gas and 
the gas must meet following conditions:
    (i) Water content is less than or equal to 0.5 lb. per million 
cubic feet at standard temperature and pressure (STP) (60 deg. F., 30 
inches Hg).
    (ii) Hydrogen Sulfide and Mercaptan Sulfur in Natural Gas is less 
than or equal to 0.1 grain per 100 cubic feet.
    (iii) Total Soluble Sulfides other than Hydrogen Sulfide must be 
less than or equal to 0.1 grain per 100 cubic feet at STP.
    (iv) Less than one percent by volume of oxygen.
    (v) Less than three percent by volume of carbon dioxide.
    (b) Pressure Limit. Pressure in a cylinder containing a permanent 
gas at 70  deg.C (158  deg.F) may not exceed the values in the 
following table:

------------------------------------------------------------------------
                                                              Percentage
                                                                  of
                                                              cylinder's
                          Division                              marked
                                                                 test
                                                               pressure
------------------------------------------------------------------------
2.3, Zone A.................................................          63
2.3, Zone B, C..............................................          70
2.1/5.1; 2.3, Zone D........................................          78
2.2.........................................................         100
------------------------------------------------------------------------

    (c) Fluorine. Fluorine must be shipped in DOT 3M or 4M cylinders 
without pressure relief devices. The settled pressure may not exceed 
\1/4\ of the cylinder's marked test pressure, or be more than 28 bar 
(400 psig) at 21  deg.C (70  deg.F). The cylinder may not contain over 
2.7 kg (6 pounds) of gas.
    (d) Carbon monoxide. A cylinder filled with carbon monoxide may not 
exceed \1/3\ of the cylinder's marked test pressure, except that if the 
gas is dry and sulfur free, settled pressure may not exceed \1/2\ of 
the cylinder's marked test pressure.
    (e) Diborane and diborane mixtures. Diborane and diborane mixed 
with a compatible compressed gas must be

[[Page 58487]]

shipped in a DOT 3M cylinder and the settled pressure may not exceed 
\1/3\ of the cylinder's marked test pressure. The maximum filling 
density of the diborane may not exceed 7 percent. Diborane mixed with a 
compatible compressed gas may not have a settled pressure exceeding \2/
3\ of the cylinder's marked test pressure if complete decomposition of 
the diborane occurs. The cylinder valve must be protected in accordance 
with Sec. 173.301(h).
    32. Section 173.304 would be revised to read as follows:


Sec. 173.304  Filling of cylinders with liquefied compressed gases.

    (a) General requirements. Liquefied compressed gases (except gas in 
solution) must be shipped in accordance with the requirements in this 
section and in Secs. 173.301, 173.301a, 173.301b, 173.304a, 173.304b 
and 173.305.
    (1) DOT 3AL, 3ALM, 3FM and 4M cylinders may not be used for any 
material that has a primary or subsidiary hazard of Class 8.
    (2) Shipments of Division 2.1 materials in aluminum cylinders are 
authorized only when transported by highway, rail or cargo-only 
aircraft.
    (b) Filling limits. Except for carbon dioxide, 1,1-Difluoroethylene 
(R-1132A), nitrous oxide and vinyl fluoride, inhibited, the liquid 
portion of a liquefied gas may not completely fill the packaging at any 
temperature up to and including 54 deg. C (130 deg. F). The liquid 
portion of vinyl fluoride, inhibited, may completely fill the cylinder 
at 54 deg. C (130 deg. F) provided; the pressure at the critical 
temperature does not exceed one and one-fourth times the service 
pressure of a nonmetric-marked cylinder; or the pressure at the 
critical temperature does not exceed 83% of the test pressure of a 
metric-marked cylinder.
    (c) Mixture of compressed gas and other material. A mixture of 
compressed gas must be shipped in accordance with Sec. 173.305.
    (d) Refrigerant gases. Refrigerant gases which are nontoxic and 
nonflammable under this part, must be offered for transportation in 
cylinders prescribed in Secs. 173.304a, 173.304b, or in DOT 2P and 2Q 
containers (Secs. 178.33, 178.33a of this subchapter). DOT 2P and 2Q 
containers must be packaged in a strong wooden or fiberboard box of 
such design as to protect valves from injury or accidental functioning 
under conditions incident to transportation. Pressure in the inside 
metal containers may not exceed 6 bar absolute (87 psia) at 21 deg. C 
(70 deg. F). Each completed metal container filled for shipment must be 
heated until its contents reach a temperature of 54 deg. C (130 deg. F) 
without evidence of leakage, distortion, or other defect. Each outside 
package must be plainly marked ``INSIDE CONTAINERS COMPLY WITH 
PRESCRIBED SPECIFICATIONS.''
    (e) Engine starting fluid. Engine starting fluid containing a 
flammable compressed gas or gases must be shipped in a cylinder as 
prescribed in Sec. 173.304a, 173.304b, or as follows:
    (1) Inside nonrefillable metal containers having a capacity not 
greater than 500 ml (32 cubic inches). The containers must be packaged 
in strong, tight outer packagings. The pressure in the container may 
not exceed 10 bar absolute (145 psia), at 54  deg.C (130  deg.F). 
However, if the pressure exceeds 10 bar absolute (145 psia), at 54 
deg.C (130  deg.F), a DOT 2P container must be used. In any event, the 
metal container must be capable of withstanding, without bursting, a 
pressure of one and one-half times the pressure of the content at 54 
deg.C (130  deg.F). The liquid content of the material and gas must not 
completely fill the container at 54  deg.C (130  deg.F). Each 
container, filled for shipment, must have been heated until its 
contents reach a temperature of 54  deg.C (130  deg.F), without 
evidence of leakage, distortion, or other defect. Each outside shipping 
container must be plainly marked, ``INSIDE CONTAINERS COMPLY WITH 
PRESCRIBED SPECIFICATIONS.''
    (2) [Reserved]
    33. Section 173.304a would be added to read as follows:


Sec. 173.304a  Additional requirements for shipment of liquefied 
compressed gases in nonmetric-marked cylinders.

    (a) Detailed filling requirements. Liquefied gases (except gas in 
solution), must be offered for transportation, subject to the 
requirements in this section and Secs. 173.301, 173.301a and 173.304, 
in nonmetric-marked cylinders, as follows:
    (1) Specification 3, 3A, 3AA, 3B, 3BN, 3E, 4B, 4BA, 4B240ET, 4BW, 
4E, 39, except that no Specification 4E or 39 packaging may be filled 
and shipped with a mixture containing a pyrophoric liquid, carbon 
bisulfide (disulfide), ethyl chloride, ethylene oxide, nickel carbonyl, 
spirits of nitroglycerin, or toxic material (Division 6.1 or 2.3), 
unless specifically authorized in this part.
    (2) The following requirements must be complied with for the gases 
named (for cryogenic liquids, see Sec. 173.316):

----------------------------------------------------------------------------------------------------------------
                                                                 Containers marked as shown in this column or of
                                          Maximum permitted      the same type with higher service pressure must
             Kind of gas                   filling  density        be used except as provided in  173.301(1),
                                        (percent) (See Note 1)      173.301(a)(4) (see notes following table)
----------------------------------------------------------------------------------------------------------------
Anhydrous ammonia....................  54.....................  DOT-4; DOT-3A480; DOT-3AA480; DOT-3A480X; DOT-
                                                                 4A480; DOT-3; DOT-4AA480; DOT-3E1800; DOT-
                                                                 3AL480.
Bromotrifluoromethane (R-13B1 or H-    124....................  DOT-3A400; DOT-3AA400; DOT-3B400; DOT-4A400; DOT-
 1301).                                                          4AA480; DOT-4B400; DOT-DOT-4BA400; DOT-4BW400;
                                                                 DOT-3E1800; DOT-39; DOT-3AL400.
Carbon dioxide (see notes 4, 7, and    68.....................  DOT-3A1800; DOT-3AX1800; DOT-3AA1800; DOT-
 8).                                                             3AAX1800; DOT-3; DOT-3E1800; DOT-3T1800; DOT-
                                                                 3HT2000; DOT-39; DOT-DOT-4L.
Carbon dioxide, refrigerated liquid    125....................  DOT-3AL1800. DOT-3A480; DOT-3AA480; DOT-3; DOT-
 (see paragraph (e) of this section.)                            3BN480; DOT-3E1800.
 Chlorine (see Note 2).
Chlorodifluroethane (R-142b) or 1-     100....................  DOT-3A150; DOT-3AA150; DOT-3B150; DOT-3E1800;
 Chloro-1, 4B150; DOT-4BA225; DOT-                               DOT-39, DOT-3AL150.
 4BW225; DOT-1-difluoroethane (Note
 8).
Chlorodifluoromethane (R-22) (see      105....................  DOT-3A240; DOT-3AA240; DOT-3B240; DOT- 4B240;
 Note 8).                                                        DOT-4BA240; DOT-4BW240; DOT-4B240ET; DOT-4E240;
                                                                 DOT-39; DOT-41; DOT-3E1800; and DOT-3AL240.
Chloropentafluorethane, (R-115)......  110....................  DOT-3A225; DOT-3AA225; DOT-3B225; DOT-4A225; DOT-
                                                                 4BA225; DOT-4B225; DOT-4BW225; DOT-3E1800; DOT-
                                                                 39; and DOT-3AL225.
Chlorotrifluoromethane (R-13) (see     100....................  DOT-3A1800; DOT-3AA1800; DOT-3; DOT-3E1800; DOT-
 Note 8).                                                        39; and DOT-3AL1800.

[[Page 58488]]

Cyclopropane (see Note 8)............  55.....................  DOT-3A225; DOT-3A480X; DOT-3AA225; DOT-3B225;
                                                                 DOT-4A225; DOT-4AA480; DOT4B225; DOT-4BA225;
                                                                 DOT-4BW225; DOT-4B240ET; DOT-3; DOT-3E1800; DOT-
                                                                 39;DOT-3AL225.
Dichlorodifluoromethane (R-12) (see    119....................  DOT-3A225; DOT-3AA225; DOT-3B225;DOT- 4A225; DOT-
 Note 8).                                                        4B225; DOT-4BA225; DOT-4BW225; DOT-4B240ET; DOT-
                                                                 4E225;DOT-9; DOT-39; DOT-41; DOT-3E1800; and
                                                                 DOT-3AL225.
Dichlorodifluoromethane and            Not liquid full at 130   DOT-3A240; DOT-3AA240, DOT-3B240; DOT-3E1800;
 difluoroethane mixture (constant       deg.F.                   DOT-4A240; DOT-4B240; DOT-4BA240; DOT-4BW240;
 boiling mixture) (R-500)(Note 8).                               DOT-4E240; DOT-9, DOT-39.
1,1-Difluoroethane (R-152a) (see Note  79.....................  DOT-3A150; DOT-3AA150; DOT-3B150;DOT-4B150; DOT-
 8).                                                             4BA225; DOT-4BW225; DOT-3E1800; DOT-3AL150.
1,1-Difluoroethylene (R-1132A).......  73.....................  DOT-3A2200, DOT-3AA2200, DOT-3AX2200, DOT-
                                                                 3AAX2200, DOT-3T2200, DOT-39.
Dimethylamine, anhydrous.............  59.....................  DOT-3A150; DOT-3AA150; DOT-3B150; DOT-4B150 DOT-
                                                                 4BA225; DOT-4BW225; ICC-3E1800.
Ethane (see Note 8)..................  35.8...................  DOT-3A1800; DOT-3AX1800; DOT-3AA1800; DOT-
                                                                 3AAX1800; DOT-3; DOT-3E1800; DOT-3T1800; DOT-
                                                                 39; DOT-3AL1800.
Ethane (see Note 8)..................  36.8...................  DOT-3A2000; DOT-3AX2000; DOT-3AA2000; DOT-
                                                                 3AAX2000; DOT-3T2000; DOT-39; DOT-3AL2000.
Ethylene (see Note 8)................  31.0...................  DOT-3A1800; DOT-3AX1800 DOT-3AA1800; DOT-
                                                                 3AAX1800; DOT-3; DOT-3E1800; DOT-3T1800; DOT-
                                                                 39; and DOT-3AL1800 .
Ethylene (see Note 8)................  32.5...................  DOT-3A2000; DOT-3AX2000; DOT-3AA2000; DOT-
                                                                 3AAX2000; DOT-3T2000; DOT-39; and DOT-3AL2000.
Ethylene (see Note 8)................  35.5...................  DOT-3A2400; DOT-3AX2400; DOT-3AA2400; DOT-
                                                                 3AAX2400; DOT-3T2400; DOT-39; DOT-3AL2400.
Hydrogen chloride, anhydrous.........  65.....................  DOT-3A1800; DOT-3AA1800; DOT-3AX1800; DOT-
                                                                 3AAX1800; DOT-3; DOT-3T1800; DOT-3E1800.
Hydrogen sulfide (see Note 10).......  62.5...................  DOT-3A480; DOT-3AA480; DOT-3B480; DOT-14A480;
                                                                 DOT-4B480; DOT-4BA480; DOT-4BW480.; DOT-3E1800;
                                                                 DOT-3AL480.
Insecticide, gases liquefied (See      Not liquid full at 130   DOT-3A300; DOT-3AA300; DOT-3B300; DOT-4B300; DOT-
 Notes 8 and 12).                       deg.F.                   4BA300; DOT-4BW300; DOT-9; DOT-40; DOT-41; DOT-
                                                                 3E1800.
Liquefied nonflammable gases, liquid   Not liquid full at 130   Specification packaging authorized in paragraph
 other than classified flammable,       deg.F.                   (a)(1) of this section and DOT-3HT; DOT 4D; DOT-
 corrosive, toxic & mixtures or                                  4DA; DOT-4DS.
 solution thereof filled w/nitrogen
 carbon dioxide, or air (see Notes 7
 and 8).
Methyl acetylene-propadiene,           Not liquid full at 130   DOT-4B240 without brazed seams; DOT-4BA240
 mixtures, stabilized (see Note 5).     deg.F.                   without brazed seams; DOT-3A240; DOT-3AA240;
                                                                 DOT-3B240; DOT-3E1800;DOT-4BW240; DOT-4E240;
                                                                 DOT-4B240ET;DOT-4;DOT-41; DOT-3AL240.
Methyl chloride......................  84.....................  DOT-3A225; DOT-3AA225; DOT-3B225; DOT-4A225; DOT-
                                                                 4B225; DOT-4BA225; DOT-4BW225; DOT-3; DOT-4;
                                                                 DOT-38; DOT-3E1800; DOT-4B240ET.
                                                                Cylinders complying with DOT-3A150; DOT-3B150;
                                                                 DOT-4A150, and DOT-4B150 manufactured prior to
                                                                 Dec. 7, 1936 are also authorized.
Methyl mercaptan.....................  80.....................  DOT-3A240; DOT-3AA240; DOT-3B240; DOT-4B240; DOT-
                                                                 4B240ET; DOT-3E1800; DOT-4BA240; DOT-4BW240.
Nitrosyl chloride....................  110....................  DOT-3BN400 only.
Nitrous oxide (see Notes 7, 8, and     68.....................  DOT-3A1800; DOT-3AX1800; DOT-3AA1800; DOT-
 11).                                                            3AAX1800; DOT-3; DOT-3E1800; DOT-3T1800; DOT-
                                                                 3HT2000; DOT-39; DOT-3AL1800.
Nitrous oxide, refrigerated liquid                              DOT-4L.
 (see paragraph (e) of this section.).
Refrigerant gas, n.o.s. or Dispersant  Not liquid full at 130   DOT-3A240; DOT-3AA240; DOT-3B240; DOT-3E1800;
 gas, n.o.s. (see Notes 8 and 13).      deg.F.                   DOT-4A240; DOT-4B240; DOT-4BA240; DOT-4BW240;
                                                                 DOT-4E240; DOT-9; DOT-39; and DOT-3AL240.
Sulfur dioxide (see note 8)..........  125....................  DOT-3A225; DOT-3AA225; DOT-3B225; DOT-4A225; DOT-
                                                                 4B225; DOT-4BA225; DOT-4BW225; DOT-4B240ET; DOT-
                                                                 3; DOT-4; DOT-38; DOT-39; DOT-3E1800; and DOT-
                                                                 3AL225.
Sulfur hexafluoride..................  120....................  DOT-3A1000; DOT-3AA1000; DOT-3AAX2400; DOT-3;
                                                                 DOT-3AL1000; DOT-3E1800; DOT-3T1800.
Sulfuryl fluoride....................  106....................  DOT-3A480; DOT-3AA480; DOT-3E1800; DOT-4B480;
                                                                 DOT-4BA480; DOT-4BW480.
Tetrafluoroethylene/inhibit..........  90.....................  DOT-3A1200; DOT-3AA1200; DOT-3E1800.
Trifluorochloroethylene, inhibited...  115....................  DOT-3A300; DOT-3AA300; DOT-3B300; DOT-4A300; DOT-
                                                                 4B300; DOT-4BA300; DOT-4BW300; DOT-3E1800.
Trimethylamine, anhydrous............  57.....................  DOT-3A150; DOT-3AA150; DOT-3B150; DOT-4B150; DOT-
                                                                 4BA225; DOT-4BW225; DOT-3E1800.
Vinyl chloride (see Note 5)..........  84.....................  DOT-4B150 without brazed seams; DOT-4BA225
                                                                 without brazed seams; DOT-4BW225; DOT-3A150;
                                                                 DOT-3AA150; DOT-3E1800; DOT-3AL150.
Vinyl fluoride, inhibited............  62.....................  DOT-3A1800; DOT-3AA1800; DOT-3E1800; DOT-
                                                                 3AL1800.

[[Page 58489]]

Vinyl methyl ether, inhibited (see     68.....................  DOT-4B150, without brazed seams; DOT-4BA225
 Note 5).                                                        without brazed seams; DOT-4BW225; DOT-3A150;
                                                                 DOT-3AA150; DOT-3B1800; DOT-3E1800.
----------------------------------------------------------------------------------------------------------------
Note 1: ``Filling density'' means the percent ratio of the weight of gas in a container to the weight of water
  that the container will hold at 60  deg.F. (1 lb of water=27.737 cubic inches at 60  deg.F.).
Note 2: Cylinders purchased after Oct. 1, 1944, for the transportation of chlorine must contain no aperture
  other than that provided in the neck of the cylinder for attachment of a valve equipped with an approved
  pressure relief device. Cylinders purchased after Nov. 1, 1935, and filled with chlorine must not contain over
  150 pounds of gas.
Note 3: [Reserved]
Note 4: Special carbon dioxide mining devices containing a heating element and filled with not over 6 pounds of
  carbon dioxide may be filled to a density of not over 85 percent, provided the cylinder is made of steel with
  a calculated bursting pressure in excess of 39,000 psi, be fitted with a frangible disc that will operate at
  not over 57 percent of that pressure, and be able to withstand a drop of 10 feet when striking crosswise on a
  steel rail while under a pressure of at least 3,000 psi. Such devices must be shipped in strong boxes or must
  be wrapped in heavy burlap and bound by 12-gauge wire with the wire completely covered by friction tape.
  Wrapping must be applied so as not to interfere with the functioning of the frangible disc pressure relief
  device. Shipments must be described as ``liquefied carbon dioxide gas (mining device)'' and marked, labeled,
  and certified as prescribed for liquefied carbon dioxide.
Note 5: All parts of valve and pressure relief devices in contact with contents of cylinders must be of a metal
  or other material, suitably treated if necessary, which will not cause formation of any acetylides.
Note 6: [Reserved]
Note 7: Specification 3HT cylinders for aircraft use only, having a maximum service life of 24 years. Authorized
  only for nonflammable gases. Cylinders must be equipped with pressure relief devices only of the frangible
  disc type which meet the requirements of Sec.  173.301(f) Each frangible disc must have a rated bursting
  pressure which does not exceed 90 percent of the minimum required test pressure of the cylinder. Discs with
  fusible metal backing are not permitted. Cylinders may be shipped only when packed in strong outside
  packagings.
Note 8: See Sec.  173.301(a)(10).
Note 9: [Reserved]
Note 10: Each valve outlet must be sealed by a threaded cap or a threaded solid plug.
Note 11: Must meet the valve and cleaning requirements in Sec.  173.302(b).
Note 12: For an insecticide gas which is nontoxic and nonflammable, see Sec.  173.305(c).
Note 13: For a refrigerant or dispersant gas which is nontoxic and nonflammable, see Sec.  173.304(d).

    (3) The internal volume of a Specification 39 cylinder may not 
exceed 75 cubic inches for a liquefied flammable gas.
    (b) [Reserved]
    (c) Verification of content in cylinder. Except as noted in 
paragraph (d)(4) of this section, the amount of liquefied gas filled 
into a cylinder must be by weight or, when the gas is lower in pressure 
than required for liquefaction, a pressure-temperature chart for the 
specific gas may be used to ensure that the service pressure at 21 deg. 
C (70 deg. F) times 5/4 will not be exceeded at 54 deg. C (130 deg. F). 
The weight of liquefied gas filled into the container also must be 
checked, after disconnecting the cylinder from the filling line, by the 
use of a proper scale.
    (d) Requirements for liquefied petroleum gas. (1) Filling density 
limited as follows:

------------------------------------------------------------------------
                                                             Maximum the
                                                               filling
                                                              density in
                                                              percent of
  Minimum specific gravity of liquid material at 60  deg.F    the water-
                                                                weight
                                                             capacity of
                                                                 the
                                                               cylinder
------------------------------------------------------------------------
0.271 to 0.289.............................................           26
0.290 to 0.306.............................................           27
0.307 to 0.322.............................................           28
0.323 to 0.338.............................................           29
0.339 to 0.354.............................................           30
0.355 to 0.371.............................................           31
0.372 to 0.398.............................................           32
0.399 to 0.425.............................................           33
0.426 to 0.440.............................................           34
0.441 to 0.452.............................................           35
0.453 to 0.462.............................................           36
0.463 to 0.472.............................................           37
0.473 to 0.480.............................................           38
0.481 to 0.488.............................................           39
0.489 to 0.495.............................................           40
0.496 to 0.503.............................................           41
0.504 to 0.510.............................................           42
0.511 to 0.519.............................................           43
0.520 to 0.527.............................................           44
0.528 to 0.536.............................................           45
0.537 to 0.544.............................................           46
0.545 to 0.552.............................................           47
0.553 to 0.560.............................................           48
0.561 to 0.568.............................................           49
0.569 to 0.576.............................................           50
0.577 to 0.584.............................................           51
0.585 to 0.592.............................................           52
0.593 to 0.600.............................................           53
0.601 to 0.608.............................................           54
0.609 to 0.617.............................................           55
0.618 to 0.626.............................................           56
0.627 to 0.634.............................................           57
------------------------------------------------------------------------

    (2) Subject to Sec. 173.301a(d), any filling density percentage 
prescribed in this section is authorized to be increased by 2 for 
liquefied petroleum gas in specification 3 cylinders or in 
specification 3A cylinders marked for 1,800 psig, or higher, service 
pressure.
    (3) Liquefied petroleum gas must be shipped in specification 
cylinders as follows:
    (i) Specification 3, 3A, 3AA, 3B, 3E, 3AL, 4B, 4BA, 4B240ET, 4BW, 
4E, or 39 cylinders. Shipments of flammable gases in 3AL cylinders are 
authorized only when transported by highway, rail or cargo-only 
aircraft.
    (ii) Additional containers may be used within the limits of 
quantity and pressure as follows:

----------------------------------------------------------------------------------------------------------------
                                               Maximum
            Type of container              capacity cubic             Maximum charging pressure--psig
                                               inches
----------------------------------------------------------------------------------------------------------------
DOT-2P or DOT-2Q (see Note 1)............           31.83  45 psig at 70  deg.F. and 105 psig at 130  deg.F.
                                                            (see Note 2).

[[Page 58490]]

DOT-2P or DOT-2Q (see Note 1)............           31.83  35 psig at 70  deg.F. and 100 psig at 130  deg.F.
----------------------------------------------------------------------------------------------------------------
Note 1: Containers must be packed in strong wooden or fiber boxes of such design as to protect valves from
  damage or accidental functioning under conditions normally incident to transportation. Each completed
  container filled for shipment must have been heated until its contents reach a temperature of 130  deg.F.,
  without evidence of leakage, distortion, or other defect. Each outside shipping container must be plainly
  marked ``INSIDE CONTAINERS COMPLY WITH PRESCRIBED SPECIFICATIONS.''
Note 2: A container must be equipped with a pressure relief device which will prevent rupture of the container
  and dangerous projection of a closing device when exposed to fire.

    (4) Verification of content. Cylinders with a water capacity of 200 
pounds or more and for use with a liquefied petroleum gas with a 
specific gravity at 60  deg.F. of 0.504 or greater may have the 
quantity of their contents determined by using a fixed length dip tube 
gauging device. The length of the dip tube shall be such that when a 
liquefied petroleum gas, with a specific volume of 0.03051 cu. ft./lb. 
at a temperature of 40  deg.F., is filled into the container the liquid 
just reaches the bottom of the tube. The weight of this liquid may not 
exceed 42 percent of the water capacity of the container which must be 
stamped thereon. The length of the dip tube, expressed in inches 
carried out to one decimal place and prefixed with the letters ``DT'' 
shall be stamped on the container and on the exterior of removable type 
dip tube; for the purpose of this requirement the marked length shall 
be expressed as the distance measured along the axis of a straight tube 
from the top of the boss through which the tube is inserted to the 
proper level of the liquid in the container. The length of each dip 
tube shall be checked when installed by weighing each container after 
filling except when installed in groups of substantially identical 
containers in which case one of each 25 containers shall be weighed. 
The quantity of liquefied gas in each container must be checked by 
means of the dip tube after disconnecting from the filling line. The 
outlet from the dip tube shall be not larger than a No. 54 drill size 
orifice. A container representative of each day's filling at each 
charging plant shall have its contents checked by weighing after 
disconnecting from the filling line.
    (e) Carbon dioxide, refrigerated liquid or nitrous oxide, 
refrigerated liquid. (1) The following provisions apply to carbon 
dioxide, refrigerated liquid and nitrous oxide, refrigerated liquid:
    (i) DOT 4L cylinders conforming to the provisions of this paragraph 
are authorized.
    (ii) Each cylinder must be protected with at least one pressure 
relief device and at least one frangible disc conforming to 
Sec. 173.301(f) and paragraph (a)(2) of this section. The relieving 
capacity of the pressure relief device system must be equal to or 
greater than that calculated by the applicable formula in paragraph 5.9 
of CGA Pamphlet S-1.1.
    (iii) The temperature and pressure of the gas at the time the 
shipment is offered for transportation may not exceed -18  deg.C (0 
deg.F) and 20 bar (290 psig) for carbon dioxide and -15.6  deg.C (+4 
deg.F) and 20 bar(290 psig) for nitrous oxide. Maximum time in transit 
may not exceed 120 hours.
    (2) The following pressure relief device settings, design service 
temperatures and filling densities apply:

----------------------------------------------------------------------------------------------------------------
Pressure relief device setting                Maximum permitted filling density (percent by weight)
  maximum start-to discharge   ---------------------------------------------------------------------------------
 gauge pressure in bar (psig)     Carbon dioxide, refrigerated  liquid      Nitrous oxide, refrigerated liquid
----------------------------------------------------------------------------------------------------------------
7.2 bar (105 psig)............  108....................................  104
11.7 bar (170 psig)...........  105....................................  101
16 bar (230 psig).............  104....................................  99
20 bar (295 psig).............  102....................................  97
25 bar (360 psig).............  100....................................  95
31 bar (450 psig).............  98.....................................  83
37 bar (540 psig).............  92.....................................  87
43 bar (625 psig).............  86.....................................  80
Design service temperature      -196  deg.C (-320  deg.F)..............  -196  deg.C (-320  deg.F)
 deg.C ( deg.F).
----------------------------------------------------------------------------------------------------------------

    34. Section 173.304b would be added to read as follows:


Sec. 173.304b  Additional requirements for shipment of liquefied 
compressed gases in metric-marked cylinders.

    (a) General requirements. Liquefied gases must be offered for 
transportation, subject to the requirements in this section, 
Secs. 173.301, 173.301b and 173.304, in the following metric-marked 
cylinders: DOT 3M, 3FM, 3ALM, and 4M. A filling factor must be 
calculated for each liquefied compressed gas to meet the following 
conditions:
    (1) The cylinder may not be liquid full at 55  deg.C (131  deg.F). 
In addition, for a low pressure liquefied compressed gas, the vapor 
space must be at least 5% of the cylinder internal volume at 50  deg.C 
(122  deg.F).
    (2) A cylinder with a marked test pressure greater than or equal to 
35 bar (508 psi) is authorized for transportation of Division 2.1, 2.2, 
and 2.3, gases Hazard Zone B, C or D gas.
    (3) A DOT 3ALM, 3M, or 3FM cylinder with a marked test pressure 
greater than or equal to 200 bar (2900 psi) is authorized for 
transportation of a Division 2.3 Hazard Zone A gas.
    (4) The pressure in a cylinder containing a high pressure liquefied 
compressed gas at 65  deg.C (149  deg.F) or low pressure liquefied 
compressed gas at 55  deg.C (131  deg.F) may not exceed the values in 
the following table:

------------------------------------------------------------------------
                                                           Percentage of
                                                            cylinder's
                        Division                            marked test
                                                             pressure
------------------------------------------------------------------------
2.3, Zone A.............................................              63
2.3, Zone B, C..........................................              70
2.1/5.1; 2.3, Zone D....................................              78
2.2.....................................................             100
------------------------------------------------------------------------


[[Page 58491]]

    (5) Vapor pressure may not exceed, at the maximum anticipated 
temperature during transportation, the cylinder's marked test pressure.
    (6) Cylinder valve and fittings must be rated at or above the 
cylinder's burst pressure. The suitability of the cylinder, valve and 
fitting materials must be checked, at the maximum anticipated 
temperature during transportation, for operation.
    (b) A DOT 3FM cylinder may not be used for a material that has a 
primary or subsidiary hazard of Class 8, hydrogen sulfide or other 
sulfide bearing compounds, carbon dioxide, carbon monoxide, atmospheric 
gases with a dew point above -50  deg.C (-58  deg.F), or any other 
material where the addition of water may make the material corrosive.
    (c) A DOT 3FM or 3ALM cylinder may not be used for reclaimed 
refrigerant gases.


Sec. 173.305  [Amended]

    35. In Sec. 173.305, paragraph (b) would be amended by revising the 
reference ``173.301(e)'' to read ``173.301a(c)''.


Sec. 173.306  [Amended]

    36. In 173.306, the following changes would be made:
    a. Paragraph (d)(3)(ii) would be amended by revising the reference 
``Sec. 173.301'' to read ``Sec. 173.301a or Sec. 173.301b''.
    b. Paragraph (g)(5) would be amended by revising the reference 
``Sec. 173.301(k)'' to read ``Sec. 173.301(a)(10)''.
    37. In 173.315, in paragraph (a), in Note 2 following the table, 
the reference ``Sec. 173.301(d)'' would be revised to read ``paragraph 
(p) of this section'' and paragraph (p) would be added to read as 
follows:


Sec. 173.315  Compressed gases in cargo tanks and portable tanks.

* * * * *
    (p) Manifolding is authorized for cargo tanks containing anhydrous 
ammonia provided that each individual cargo tank is equipped with a 
pressure relief valve or valves and gauging devices as required by 
paragraphs (h) and (i) of this section. Each valve shall be tightly 
closed while the cargo tank is in transit. Each cargo tank must be 
filled separately.
    38. Section 173.334 would be revised to read as follows:


Sec. 173.334  Organic phosphates mixed with compressed gas.

    Hexaethyl tetraphosphate, parathion, tetraethyl dithio 
pyrophosphate, tetraethyl pyrophosphate, or other Division 6.1 organic 
phosphates (including a compound or mixture), may be mixed with a non-
flammable compressed gas. This mixture must not contain more than 20 
percent by weight of organic phosphate and must be packaged in 
specification 3A240, 3AA240, 3B240, 4A240, 4B240, 4BA240, or 4BW240 
cylinders; or any 3M, 3FM, or 4M cylinders with a marked test pressure 
of at least 25 bar (363 psig) or greater; meeting the following 
requirements:
    (a) Each cylinder may be filled with not more than 5 kg (11.0 
pounds) of the mixture, to a maximum filling density of not more than 
80 percent of the water capacity;
    (b) No cylinder may be equipped with an eduction tube or a fusible 
plug;
    (c) No cylinder may be equipped with any valve unless the valve is 
a type approved by the Associate Administrator for Hazardous Materials 
Safety;
    (d) Cylinders must be overpacked in a box, crate or other strong 
outside packaging conforming to the requirements of Sec. 173.25 and 
arranged to protect each valve or other closing device from damage. 
Except as provided in paragraph (e) of this section, no more than four 
cylinders may be packed in a strong outside packaging. Each strong 
outside packaging with its closing device protection must be 
sufficiently strong to protect all parts of each cylinder from 
deformation or breakage if the completed package is dropped 1.8 m (6 
feet) onto a nonyielding surface and impacted at the package's weakest 
point;
    (e) Cylinders may be packed in strong wooden boxes with valves or 
other closing devices protected from damage, with not more than twelve 
cylinders in one outside wooden box. An outer fiberboard box may be 
used when not more than four such cylinders are to be shipped in one 
packaging. Valves must be adequately protected. Box and valve 
protection must be of strength sufficient to protect all parts of inner 
packagings and valves from deformation or breakage resulting from a 
drop of at least 1.8 m (6 feet) onto a nonyielding surface, impacting 
at the weakest point.
    39. Section 173.336 would be revised to read as follows:


Sec. 173.336  Nitrogen dioxide, liquefied, or dinitrogen tetroxide, 
liquefied.

    Nitrogen dioxide, liquefied, or dinitrogen tetroxide, liquefied, 
must be packaged in specification cylinders as prescribed in 
Sec. 173.192. Specification cylinders prescribed in Sec. 173.192 with 
valve removed are authorized. Each valve opening must be closed by 
means of a solid metal plug with tapered thread properly luted to 
prevent leakages. Transportation in DOT 3AL and 3ALM cylinders is 
authorized only by highway or rail. Each cylinder must be cleaned in 
compliance with the requirements of Federal Specification RR-C-901c, 
paragraphs 3.7.2 and 3.8.2. Cleaning agents equivalent to those 
specified in RR-C-901b may be used; however, any cleaning agent must 
not be capable of reacting with oxygen. One cylinder selected at random 
from a group of 200 or less and cleaned at the same time must be tested 
for oil contamination in accordance with Specification RR-C-901c 
paragraph 4.4.2.3 and meet the standard of cleanliness specified 
therein.
    40. Section 173.337 would be revised to read as follows:


Sec. 173.337  Nitric oxide.

    Nitric oxide must be packed in Specification 3A1800, 3AA1800, 
3E1800, or 3AL1800 cylinders; or 3M, 3ALM, or 3FM cylinders with a 
marked test pressure of 200 bar (2900 psig) or greater filled to a 
pressure of not more than 52 bar (750 psi) at 21  deg.C (70  deg.F). 
Cylinders must be equipped with a stainless steel valve and valve seat 
which will not be deteriorated by contact with nitric oxide or nitrogen 
dioxide. Cylinders or valves may not be equipped with pressure relief 
devices of any type. Valve outlets must be sealed by a solid threaded 
cap or plug and an inert gasketing material. In addition--
    (a) Transportation in 3AL or 3ALM cylinders is authorized only by 
highway or rail.
    (b) Each cylinder must be cleaned in compliance with the 
requirements of Federal Specification RR-C-901c, paragraphs 3.7.2 and 
3.8.2. Cleaning agents equivalent to those specified in RR-C-901c may 
be used; however, any cleaning agent must not be capable of reacting 
with oxygen. One cylinder selected at random from a group of 200 or 
less and cleaned at the same time must be tested for oil contamination 
in accordance with Specification RR-C-901C paragraph 4.4.2.3 and meet 
the standard of cleanliness specified therein.

PART 177--CARRIAGE BY PUBLIC HIGHWAY

    41. The authority citation for Part 177 would continue to read as 
follows:

    Authority: 49 U.S.C. 5101-5127, 49 CFR 1.53.

    42. In Sec. 177.840, paragraph (a)(1) would be revised to read as 
follows:


Sec. 177.840  Class 2 (gases) materials.

* * * * *
    (a) * * *

[[Page 58492]]

    (1) Cylinders. Cylinders containing Class 2 (gases) materials shall 
be securely lashed in an upright position, loaded in racks, or packed 
in boxes or crates and securely attached to the motor vehicle to 
prevent the cylinders from being shifted, overturned or ejected from 
the vehicle. A cylinder containing a Class 2 material may be loaded in 
a horizontal position provided that the cylinder is designed so that 
the inlet to the pressure relief device is located in the vapor space 
and the cylinder is properly secured and lashed.
* * * * *

PART 178--SPECIFICATIONS FOR PACKAGINGS

    43. The authority citation for part 178 would continue to read as 
follows:

    Authority: 49 U.S.C. 5101-5127; 49 CFR 1.53.


Sec. 178.3  [Amended]

    44. In Sec. 178.3, paragraph (a)(1) would be amended by removing 
the wording ``DOT 4B240ET'' and adding the wording ``DOT 3M'', in its 
place.


Sec. 178.35  [Amended]

    45. In Sec. 178.35, the following changes would be made:
    a. In paragraph (b) introductory text, the wording ``Sec. 173.300b 
of this subchapter'' would be revised to read ``subpart I of part 107 
of this chapter''.
    b. In paragraph (b)(1), the wording ``Sec. 173.300a of this 
subchapter'' would be revised to read ``subpart I of part 107 of this 
chapter''.
    c. In paragraph (e), the wording ``Secs. 173.34 and 173.301'' would 
be revised to read ``Sec. 173.301''.
    d. In paragraph (f)(2)(ii), the parenthetical wording 
``(Sec. 178.44)'' and ``(Sec. 178.45)'' would be removed.
    46. In addition, in Sec. 178.35, paragraph (f)(3) would be revised 
to read as follows:


Sec. 178.35  General requirements for specification cylinders.

* * * * *
    (f) * * *
    (3) Marking exceptions. A DOT 3E cylinder is not required to be 
marked with an inspector's mark or a serial number.
* * * * *


Secs. 178.36, 178.37, 178.38, 178.39, 178.45  [Removed]

    47. In subpart C, Secs. 178.36, 178.37, 178.38, 178.39, and 178.45 
would be removed.
    48. In Sec. 178.46(a)(4), in Table 2, the entry ``6351-T6'' would 
be removed and Table 1 would be revised to read as follows:


Sec. 178.46  Specification 3AL seamless aluminum cylinders.

    (a) * * *
    (4) * * *

                                                                   Table 1.--Aluminum
            [Heat or Cast Analysis for Aluminum; similar to ``Aluminum Association \1\ '' Alloy 6061 Chemical Analysis in Weight Percent \2\]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                   Other
                                                                                                                            ------------------
          Si  min/max           Fe  max  Cu  min/max  Mn  max  Mg  min/max  Cr  min/max  Zn  max  Ti  max  Pb  max  Bi  max    Each    Total       Al
                                                                                                                               max      max
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.40/0.8......................      0.7     0.15/0.4     0.15      0.8/1.2    0.04/0.35     0.25     0.15    0.005    0.005     0.05     0.15  Bal.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The ``Aluminum Association'' refers to ``Aluminum Standards and Data 1993'', published by the Aluminum Association Inc.
\2\ Except for ``Pb'' and ``Bi'', the chemical composition corresponds with that of Table 1 of ASTM B221 for Aluminum Association alloy 6061.

* * * * *


Secs. 178.50, 178.51 and 178.55  [Removed]

    49. Sections 178.50, 178.51, and 178.55 would be removed.


Sec. 178.56  [Amended]

    50. In Sec. 178.56, paragraph (b) would be amended by revising the 
wording ``Table 1 of Appendix A to this part'' to read ``Table 1 of 
Appendix A to this subpart''.


Sec. 178.60  [Amended]

    51. In Sec. 178.60, paragraph (b) would be amended by revising the 
wording ``Table 1 of Appendix A to this part'' to read ``Table 1 of 
Appendix A to this subpart''.


Sec. 178.61  [Removed]

    52. Section 178.61 would be removed.


Sec. 178.68  [Removed]

    53. Section 178.68 would be removed.
    54. Section 178.69 would be added to Subpart C to read as follows:


Sec. 178.69  Applicability and design criteria for all metric-marked 
DOT specification cylinders.

    (a) Applicability. The definitions and general requirements 
prescribed in paragraphs (b) through (g) of this section apply to the 
manufacture of cylinders to the DOT 3M, 3ALM, 3FM and 4M specifications 
prescribed in Secs. 178.70 through 178.81. The requirements for design 
qualification tests and production tests and verifications prescribed 
in paragraphs (h) and (i) of this section apply only when required by 
the individual specification. All specification requirements are 
minimum requirements.
    (b) Definitions. For purposes of this subpart--
    Associate Administrator means the Associate Administrator for 
Hazardous Materials Safety.
    Design qualification tests means a series of tests, including the 
cycle, burst and puncture resistance test, that measure the structural 
integrity of a cylinder design or significant design change.
    Heat treatment means heating and cooling a solid metal or alloy in 
such a way as to obtain desired conditions or properties. In addition:
    (1) Quench and temper heat treatment means the process of heat 
treating and cooling cylinders by liquid quenching. The liquid must 
have a cooling rate of less than 80 percent of that of water. The 
temperature on quenching shall be appropriate for the material of 
construction but may not exceed 957 deg.C (1750 deg.F).
    (2) Normalizing heat treatment means heating a ferrous alloy to a 
suitable temperature above its transformation temperature, not to 
exceed 957 deg.C (1750 deg.F), and then cooling it in air to ambient 
temperature.
    (3) Annealing heat treatment means heating to and holding at a 
suitable temperature and then cooling to facilitate cold working.
    (4) Stress relieving heat treatment means heating to a suitable 
temperature, holding long enough to reduce residual stresses and then 
cooling slowly enough to minimize the development of new residual 
stresses.
    Lot means a group of cylinders successively produced in a work 
shift of not more than 10 hours of continuous operation having--
    (1) The same specified size and configuration, within the 
parameters of ``significant change'' to an original design as defined 
in this section;
    (2) The same specified material of construction (i.e. cast or 
heat);
    (3) The same process of manufacture; and

[[Page 58493]]

    (4) Been subjected to similar conditions of time, temperature, 
cooling rate, and atmosphere during heat treatment.
    Plugged cylinder is a cylinder with a permanent end closure 
achieved by the insertion of a threaded plug.
    Proof pressure test means a pressure test by interior 
pressurization without the determination of the cylinder's expansion.
    Settled pressure, (formerly referred to as service pressure) means 
the pressure of the contents of the cylinder at 15  deg.C (59  deg.F).
    Significant change to an original design means--
    (1) A 10 percent or greater change in cylinder wall thickness, test 
pressure or diameter;
    (2) A 30 percent or greater change in water capacity or base 
thickness;
    (3) Any change in specified material;
    (4) An increase in the diameter of openings of over 100 percent; or
    (5) Any change in the number of openings.
    Spun cylinder is a cylinder with an end closure that has been 
welded by the spinning process.
    Volumetric expansion test means a pressure test by interior 
pressurization to measure a cylinder's expansion by using the water 
jacket or direct expansion methods.
    (1) Water jacket method means a volumetric expansion test to 
determine a cylinder's total and permanent expansion by measuring the 
difference between the volume of water the cylinder externally 
displaces at test pressure and the volume of water the cylinder 
externally displaces at ambient pressure
    (2) Direct expansion method means a volumetric expansion test to 
calculate a cylinder's total and permanent expansion by measuring the 
amount of water forced into a cylinder at test pressure, adjusted for 
the compressibility of water, as a means of determining the expansion.
    (c) Inspection and analyses. Inspection and analyses must be in 
compliance with the following:
    (1) Inspections and verifications, as required, must be performed 
by a hazmat employee of an independent inspection agency that has been 
approved in writing by the Associate Administrator in accordance with 
Sec. 107.803 of this chapter.
    (2) Chemical analyses and tests must be made in the United States 
or at a facility located outside the United States that is approved in 
writing by the Associate Administrator in accordance with Sec. 107.807 
of this chapter and under the supervision of an independent inspection 
agency approved under Sec. 107.803 of this chapter.
    (d) Authorized material and material identification. (1) Material 
of construction must be of uniform quality.
    (2) Materials with seams, cracks, laminations or other defects 
likely to weaken the finished cylinder may not be used.
    (3) Materials must be identified with the heat or cast code by a 
suitable method during manufacture. If the heat or cast identification 
is permanently stamped on the cylinder, it must be stamped in an area 
other than the sidewall of the cylinder.
    (e) Duties of the inspector. The inspector shall determine that 
each cylinder conforms to the requirements in this section and the 
applicable individual specification. In making these determinations, 
the inspector shall:
    (1) Verify that all procedures for obtaining and reporting the 
chemical analysis are in accordance with the appropriate requirements 
of ASTM Chemical Analysis Test Methods and that the chemical analysis 
is in conformance with the individual specification by--
    (i) Obtaining a certified cast or heat analysis from the material 
producer, supplier, or from the cylinder manufacturer, for each heat or 
cast of material; or
    (ii) Peforming or obtaining a check (solid metal) analysis, when 
such check analysis is required;
    (2) Witness that the applicable design qualification tests 
prescribed in paragraph (h) of this section for each new cylinder 
design or a significant change to an original design have been 
performed with satisfactory results;
    (3) Select samples for all tests;
    (4) Select samples for the check analysis, when performed;
    (5) Verify that identification of material is proper;
    (6) Verify that the manufacturer makes a complete internal 
inspection of the cylinder body before closing the ends;
    (7) Verify that wall thickness was measured and that the specified 
minimum thickness is met;
    (8) Verify that the heat treatment is proper;
    (9) Witness each test (except that results of the hardness test and 
the grain size test may be verified);
    (10) Verify by gauge that threads are in conformance with the 
specification;
    (11) Verify that each cylinder is marked in accordance with the 
applicable specification;
    (12) Verify that gauges and test equipment are properly calibrated;
    (13) Prepare a report containing, at a minimum, the information 
required by the applicable provisions of this subpart and the 
information listed in CGA Pamphlet C-11 and provide the report to the 
manufacturer and, upon request, to the purchaser. The inspector must 
retain the reports required by this section and the applicable 
individual specification for 15 years from the original test date on 
the cylinder. Each report must be legible and in English; and
    (14) Certify that all cylinders represented by the test report meet 
all applicable requirements of the specification through inspection, 
verification, or any other action required to assure compliance.
    (f) Threads. Threads must conform to the following:
    (1) Each thread must be clean cut, even, without checks and to 
gauge.
    (2) Taper threads must conform to one of the following--
    (i) American Standard Pipe Thread (NPT) type must conform to the 
requirements of Federal Standard H-28, Section 7 (FED-STD-H28/7A);
    (ii) National Gas Taper thread (NGT) type must conform to the 
requirements of Federal Standard H-28 Sections 7 (FED-STD-H28/7A), and 
9 (FED-STD-H28/9A);
    (iii) Other taper threads conforming to other standards may be used 
provided the total thread shear strength is not less than that 
specified for NPT threads.
    (3) Straight threads must conform to one of the following--
    (i) National Gas Straight Thread (NGS) type must conform to the 
requirements of Federal Standard H-28, Sections 7 (FED-STD-H28/7A), and 
Section 9 (FED-STD-H28/9A);
    (ii) Unified Thread (UN) type must conform to the requirements of 
Federal Standard H-28, Section 2 (FED-STD-H28/2B);
    (iii) Controlled Radius Root Thread (UNJ) type must conform to the 
requirements of Federal Standard H-28, Section 4 (FED-STD-H28/4);
    (iv) Other straight thread types conforming to other standards may 
be used provided the requirements of paragraph (f)(4) of this section 
are met.
    (4) All straight threads must have at least 4 engaged threads, a 
tight fit, and calculated shear strength of at least 10 times the shear 
stress at the test pressure of the cylinder. Shear strength must be 
calculated by using the appropriate thread shear area in accordance 
with Federal Standard H-28 Section 2, Appendix B (FED-STD-H28/2B 
Appendix B). Gaskets are required to prevent leakage.

[[Page 58494]]

    (g) Pressure relief devices and protection for valves, pressure 
relief devices, fittings and connections. (1) Pressure relief devices 
on cylinders must conform to the requirements of Sec. 173.301(f) of 
this subchapter.
    (2) Protection for valves, pressure relief devices, fittings and 
connections must conform to the requirements of Sec. 173.301(h)(2) of 
this subchapter.
    (h) Design qualification tests. Each cylinder design and each 
cylinder design having a ``significant change'' from the original 
design must be subjected to the design qualification tests prescribed 
in this paragraph (h).
    (1) Cycle test. The cycle test must be performed on a cylinder 
after it has passed the volumetric expansion test, by subjecting it to 
successive hydraulic pressurization and depressurization cycles. The 
rate of cycling may not exceed 10 cycles per minute.
    (i) The lower cyclic pressure may not exceed 10 percent of the 
upper cyclic pressure. The upper cyclic pressure must be at least equal 
to the prescribed minimum test pressure.
    (ii) The test cylinder must be subjected to a pressure exceeding 90 
percent of the upper cyclic pressure for at least 20 percent of the 
duration of each cycle.
    (iii) The cycle test must be performed on at least three 
representative samples of each design or any significant change to an 
original design.
    (iv) All cylinders used in the cycle test must be rendered 
incapable of holding pressure following completion of the cycle test.
    (2) Burst test. The burst test must be performed on a 
representative completed cylinder selected at random after heat 
treatment by hydraulically pressurizing the cylinder to failure. The 
rate of pressurization may not exceed 14 bar (200 psi) per second. 
Burst testing of each design or any significant change to a previously 
tested design must be performed on at least 3 representative cylinders.
    (3) Puncture resistance test. Each cylinder design type intended 
for the transportation of Division 2.3 gases or Division 6.1 liquids in 
Hazard Zones A and B must pass the following test. Cylinders that are 
shipped in an overpack must be tested in the overpack.
    (i) The puncture resistance test must be performed on three 
representative cylinders selected at random after heat treatment. The 
cylinder must be filled with water and pressurized to \2/3\ the marked 
test pressure at 21 deg. C (70 deg. F). The cylinder must be tested on 
its sidewall, supported on an unyielding support and tied down so that 
there is no movement during impact. The puncturing probe must consist 
of a 2 inch x 2 inch x \1/4\ inch angle iron, its end sawed off at 
90 deg. to form a sharp corner. The probe must have a weight attached 
that is equivalent to the weight of the cylinder including the heaviest 
material to be shipped. The probe must be dropped from a minimum height 
of 2.1m (7 feet) from the top surface of the cylinder, perpendicular to 
the cylinder's longitudinal centerline, and must impact the cylinder 
sidewall on the top of the cylinder. The sharp corner of the angle iron 
must impact the centerline of the cylinder. (See Figure 1 of this 
section.)
    (ii) There must be no leakage as a result of the impact. The 
cylinder must be leak tested, using compressed gas charged to 2/3 of 
the marked test pressure.
    (4) Acceptable test results. Acceptable design qualification test 
results are as prescribed in the individual cylinder specification.
    (i) Production tests and verifications. When the individual 
specification requires a particular production test to be performed, 
the test must be conducted on the finished cylinder as prescribed in 
this paragraph (i). Unless otherwise noted in this section, acceptable 
test results are prescribed in the individual cylinder specification. 
Any lot not meeting acceptable test results must be rejected:
    (1) Flattening or bend test. Flattening or bend tests must be 
performed, on a representative completed cylinder selected at random 
or, if authorized by the individual specification on a test ring, after 
heat treatment. Each test ring used for the test must meet the 
requirements of paragraph (i)(7) of this section.
    (i) During the flattening test, the cylinder or test ring must be 
flattened between wedge-shaped knife edges with the longitudinal axis 
of the cylinder at approximately 90 degrees to the knife edges. For 
steel and nickel cylinders, the knife edges must have a 60 degree 
included angle and be rounded to a 13 mm (1/2 inch) radius. For 
aluminum cylinders, see Sec. 178.72(i)(4).
    (ii) A bend test in accordance with ASTM E 290 may be substituted 
for the flattening test. Two test pieces cut from a sidewall ring or 
rings shall be tested. The width shall be the greater of 25 mm (1 inch) 
or four times the thickness of the test specimen. A load shall be 
applied to the inside surface of the test piece by a mandrel at the 
mid-length until the interior edges are no further apart than the 
mandrel diameter. For steel cylinders the mandrel shall not be greater 
than four times the actual wall thickness.
    (iii) For a cylinder with a water capacity of 454 kg (1,000 pounds) 
or less, the flattening or bend test must be performed on a cylinder 
selected from each lot.
    (iv) For a cylinder with a water capacity exceeding 454 kg (1,000 
pounds), the flattening or bend test must be performed on a cylinder or 
on a test ring out of each lot when cylinders are heat treated in a 
batch furnace, or from one cylinder or test ring out of each four hours 
or less of production when the cylinders are heat treated in a 
continuous furnace.
    (v) A retest using one additional set of specimens is authorized if 
a test was considered improper due to the presence of a fault in the 
equipment or specimen preparation. Retest specimens must be taken from 
this same cylinder if space permits or from another randomly selected 
cylinder in the same lot.
    (2) Grain size. For cylinders made from nickel, preparation and 
examination of the specimen and grain size calculation must be as 
prescribed in ASTM E 112.
    (3) Hardness test. Apparatus and procedures must be in conformance 
with ASTM E 18 for Rockwell C scale (HRC) hardness number or ASTM E 10 
for Brinell hardness number (HBS).
    (4) Impact test. The impact test must be performed on specimens 
taken from the cylinder or, if authorized by the individual 
specification, from a test ring, after heat treatment. Each test ring 
used for the test must meet the requirements of paragraph (i)(7) of 
this section. Impact specimens must be prepared and tested in 
accordance with ASTM E 23 and the specific requirements in the 
individual specification. A cylinder or a test ring need represent only 
one of the heats in the lot, provided the other heats in the lot were 
heat treated under the same conditions and have previously been tested 
and have passed the tests.
    (i) For a cylinder with a water capacity of 454 kg (1,000 pounds) 
or less, the specimens must be taken from one cylinder or test ring out 
of each lot.
    (ii) For a cylinder with a water capacity exceeding 454 kg (1,000 
pounds), the specimens must be taken from one cylinder or test ring out 
of each batch when cylinders are heat treated in a batch furnace, or 
from one cylinder or test ring out of each 4 hours or less of 
production when cylinders are heat treated in a continuous furnace.
    (5) Leakage test. Spun cylinders must be tested for leakage by 
subjecting the inside of the finished bottom to a

[[Page 58495]]

pressure of not less than \1/2\ of the cylinder's marked test pressure. 
The bottom must be clean and free from all moisture. Pressure must be 
applied, using dry gas, over an area of at least six percent of the 
total area of the bottom but not less than 19 mm (\3/4\ inch) in 
diameter including the closure. The required pressure must be applied 
for at least one minute, during which time the outside of the bottom 
under test must be covered with water or other suitable leak detecting 
fluid and closely examined for indication of leakage. The leakage test 
must be performed prior to the closing of the cylinder. The cylinder 
may not show any evidence of leakage.
    (6) Magnetic particle and liquid penetrant examinations. The 
apparatus and procedures for the magnetic particle examination, wet or 
dry method, must conform to ASTM E 709. The apparatus and procedures 
for the liquid penetrant inspection must conform to ASTM E 165.
    (7) Mechanical tests. Unless otherwise specified in the individual 
cylinder specification, a mechanical test must be performed on a 
minimum of two specimens taken at least 160 degrees apart from a 
representative completed cylinder which is selected at random after 
pressure testing and heat treatment. For cylinders more than 2 meters 
(6.5 feet) long, the mechanical test may be performed on a test ring 
which has been heat treated with the completed cylinders. The test ring 
must be at least 61 cm (24 inches) long and must have its ends covered 
during heat treatment so as to simulate the heat treatment process of 
the finished cylinder it represents. Each test ring used for the test 
must be of the same specification material, diameter and thickness as 
the finished cylinder it represents. A test cylinder or test ring need 
represent only one of the heats in the lot provided the other heats in 
the lot have previously been tested and have passed the tests.
    (i) Specimens must conform to the following:
    (A) The long axis of the specimen must be parallel to the 
longitudinal axis of the cylinder.
    (B) The tensile specimen reduced section may not be flattened. 
However, the grip ends may be flattened to within 25 mm (1 inch) of 
each end of the reduced section.
    (C) Temperatures generated during the preparation of a specimen may 
not exceed 204  deg.C (400  deg.F) for steel or nickel, or 121  deg.C 
(250  deg.F) for aluminum.
    (ii) The tensile strength, yield strength, and elongation of the 
material must be determined as follows:
    (A) The yield strength in tension must be the stress corresponding 
to a permanent strain of 0.2 percent of the gauge length.
    (B) For steel and nickel, the yield strength must be determined by 
the ``offset'' method or the extension under-load method described in 
ASTM E 8. For aluminum material, the yield strength must be determined 
by the ``offset'' method or the extension under load method as 
described in ASTM B 557.
    (C) The cross-head speed of the testing machine may not exceed 3 mm 
(\1/8\ inch) per minute during the determination of yield strength, 
however, any test speed may be used until one-quarter of the specified 
tensile strength is reached.
    (D) The specimens must be taken from one cylinder selected from 
each lot.
    (E) When the length of the cylinder does not permit securing 
straight specimens, then specimens may be taken in any location or 
direction and may be straightened or flattened cold, by pressure only, 
not by blows. The inspector's report must indicate that the specimens 
were taken and prepared in this manner.
    (F) The size of the specimen must be one of the following--
    (1) gauge length of 50 mm (2 inches) and a maximum width of 38 mm 
(1.5 inches);
    (2) gauge length of 200 mm (8 inches) and a maximum width of 38 mm 
(1.5 inches); or
    (3) gauge length of at least 24 times specimen actual thickness and 
a maximum width of 6 times actual thickness, provided that the cylinder 
wall is not over 4.7 mm (\3/16\ inch) thick.
    (G) For a cylinder with a water capacity exceeding 454 kg (1,000 
pounds):
    (1) The specimens must be taken from one cylinder or test ring out 
of each batch when cylinders are heat treated in a batch furnace or 
from one cylinder or test ring out of each 4 hours or less of 
production when cylinders are heat treated in a continuous furnace.
    (2) The size of the specimen must be as prescribed in the 
individual specification.
    (iii) A retest using one additional set of specimens is authorized 
if a test was considered improper due to a fault in the equipment or 
specimen preparation. Retest specimens must be from the same cylinder 
if space permits, or from another randomly selected cylinder from the 
same lot.
    (8) Mechanical tests of welds. (i) Tensile test: Specimens must be 
prepared in accordance with and meet the requirements of CGA Pamphlet 
C-3. Should any specimen from the first test fail to meet the 
requirements, a second test may be performed taken from three 
additional cylinders selected at random from the same lot. If either of 
the additional specimens fails to meet the requirements of CGA Pamphlet 
C-3, the entire lot must be rejected.
    (ii) Guided bend test: Specimens must be prepared in accordance 
with and meet the requirements of CGA Pamphlet C-3.
    (iii) Alternate guided-bend test: This test may be used as an 
alternative to the guided bend test specified in paragraph (i)(8)(ii) 
of this section and must be performed in accordance with CGA Pamphlet 
C-3. The specimen shall be bent until the elongation at the outer 
surface, adjacent to the root of the weld, between the lightly scribed 
gauge lines--``a'' to ``b'', shall be at least 20 percent, except that 
this percentage may be reduced for steels having a tensile strength in 
excess of 340 MPa (50,000 psi), as provided in table 4 of Sec. 178.81.
    (9) Production burst test. When required by a particular 
specification, must be performed on at least one cylinder from each 
lot. A cylinder used in the cycle test may be used for the production 
burst test. If a cylinder fails the production burst test, a second 
sample of three cylinders from the same lot must be selected by the 
independent inspector. If any of these tested cylinders fail, the lot 
must be rejected.
    (10) Proof pressure test. The pressure for the proof pressure test 
must be at least equal to the marked test pressure and must be 
maintained for at least ten seconds, and sufficiently longer, as 
necessary, to assure there is no leakage and no drop in pressure. The 
cylinder may show no evidence of leakage or distortion.
    (11) Radiographic examination. Radiographic examination of 
cylinders must conform to the techniques and acceptability criteria set 
forth in CGA Pamphlet C-3. When fluoroscopic examination is used, 
permanent film records need not be retained.
    (12) Ultrasonic examination. The ultrasonic examination must be 
performed on the cylindrical section of the completed cylinder after it 
has passed the volumetric expansion test. Testing must be in accordance 
with Appendix B of this subpart.
    (13) Volumetric expansion test. After heat treatment, each cylinder 
must be subjected to an internal pressure at least equal to the marked 
test pressure. The water jacket method must be performed in accordance 
with paragraph 4 and Appendices A and B of CGA Pamphlet C-1. An 
alternative test procedure, such as direct expansion, may be used when

[[Page 58496]]

approved in writing by the Associate Administrator. If the required 
test pressure can not be maintained due to failure of test apparatus, 
the cylinder must be rejected or the test must be repeated at a 
pressure increased by 10 percent of the test pressure or 7 bar (100 
psi) whichever is lower. Only two retests are authorized. The permanent 
expansion measured at zero gauge pressure may not exceed 10 percent of 
the total measured expansion at test pressure.
    (j) Rejected cylinders. When a lot of cylinders is rejected, and 
reheat treatment may correct the cause of rejection, the lot may be 
reheat treated and retested as if it were a new lot.
    (1) Volumetric expansion test: Reheat treatment of rejected 
cylinders that failed due to excessive permanent expansion is 
authorized.
    (2) Magnetic particle, liquid penetrant and ultrasonic 
examinations: Any cylinder rejected because of cracks may not be 
requalified.
    (k) Markings. Required markings on the cylinder must be in 
accordance with the following:
    (1) Each cylinder must be legibly and permanently marked by 
stamping on the shoulder, top head or neck. The depth of marking must 
ensure that the wall thickness measured from the root of the stamping 
to the interior surface is equal to or greater than the prescribed 
minimum wall thickness.
    (2) For a DOT-4M specification cylinder the required markings must 
be stamped plainly and permanently on the shoulders, top head, neck, 
valve boss, valve protection sleeve, collar, or similar part 
permanently attached to the top of the cylinder. For cylinders that do 
not exceed 11.3 kg (25 pounds) water capacity, the marking may be on 
the footring permanently attached to the cylinder.
    (3) The required markings specified in this paragraph (k) (3) must 
be stamped on the cylinder in the sequence shown in items 1 through 12, 
with no additional information interspersed, as illustrated in the 
following example:
DOT-3M/USA/M1234/SN123456/UT/200BAR/IA01/98-09/250/5.8/SS/56.5
Where:

1. DOT 3M = DOT specification number.
2. USA = country of manufacture.
3. M1234 = symbol of manufacturer assigned by the Associate 
Administrator.
4. SN123456 = manufacturer's serial number.
5. UT = stamp for non-destructive ultrasonic examination, if 
applicable.
6. 200BAR = test pressure (bar).
7. IA01 = Independent Inspection mark.
8. 98-09 = date of test (year and month).
9. 250 = water capacity (liters).
10. 5.8 = minimum guaranteed wall thickness (millimeters).
11. SS = identification of alloy (SS:stainless steel, NI:Nickel, AL: 
Aluminum CS: Carbon Steel).
12. 56.5 = tare weight (kilograms).

    (4) Required markings must be at least 6 mm (0.250 inch) high, 
except that cylinders having an inside diameter less than 102 mm (4 
inches) may have markings that are at least 3 mm (0.116 inch) high.
    (5) Stamping on the side wall is prohibited.
    (6) No other markings may conflict with the required markings.
    (7) Other variations in stamping required marks is authorized only 
when necessitated by lack of space or as approved in writing by the 
Associate Administrator.
    (l) Coatings. Coatings on a cylinder's exterior or interior walls 
are authorized, except that the coating must not cause markings to be 
illegible, obscure defects, or allow moisture to be trapped between the 
cylinder wall and the coating. Any coating that may prevent adequate 
visual inspection or ultrasonic examination is prohibited.

BILLING CODE 4910-60-P

[[Page 58497]]

Figure 1 to Sec. 178.69
[GRAPHIC] [TIFF OMITTED] TP30OC98.000


[[Page 58498]]


    55. Section 178.70 would be added to Subpart C to read as follows:


Sec. 178.70  General requirements for DOT 3 series metric-marked 
seamless cylinders.

    (a) DOT specifications 3M (Sec. 178.71), 3ALM (Sec. 178.72), and 
3FM (Sec. 178.73) cylinders must meet the requirements contained in 
this section, Sec. 178.69, and the requirements of the applicable 
individual specification contained in Secs. 178.71 through 178.73.
    (b) Lot size. In no case may a lot exceed 200 cylinders, but any 
cylinder processed for use in the required destructive testing need not 
be counted as being one of the 200.
    (c) Authorized material and identification of material. All tubing, 
billet, sheet, plate or cast stock must be in conformance with one of 
the specifications in Table 1 or 2 of Appendix A of this subpart. The 
inspector may require a check analysis to establish the heat or cast 
analysis when necessary to meet the requirements of Sec. 178.69(c)(2). 
The material may not be used if the results of such analysis indicates 
nonconformance with the requirements of the material specification.
    (d) Manufacture. (1) Each cylinder must be of seamless construction 
with integrally formed heads and bottoms.
    (2) The manufacturing process must be capable of producing a 
cylinder that is free from defects likely to weaken the finished 
cylinder. For a cylinder with a water capacity of more than 454 kg 
(1000 pounds), permanent closures formed by spinning are prohibited and 
integral heads must be concave to pressure.
    (3) Dirt and scale must be removed to permit proper inspection. 
Each cylinder must have a smooth and uniform finish. Fissures, laps, 
tears, or other defects that are likely to weaken the finished cylinder 
are not acceptable. The thickness of the treated areas must be measured 
and may not be less than the prescribed minimum sidewall thickness. 
Machining or other treatment of the cylinder to eliminate defects must 
be completed before heat treatment and volumetric expansion testing.
    (4) Head and bottom configurations must be as follows:
    (i) Bottoms of bumped-back cylinders must have a minimum thickness 
of not less than two times the prescribed minimum sidewall thickness. 
Such bottom thickness must be measured within an area bounded by a line 
representing the points of contact between the cylinder and the floor 
when the cylinder is in a vertical position.
    (ii) For heads and bottoms concave to pressure, the inside shape 
must be hemispherical, ellipsoidal, or torispherical with a major to 
minor axis not exceeding 2 to 1, or a dished shape falling within these 
limits. Such heads and bottoms must be at least the prescribed minimum 
wall thickness of the cylindrical shell, except as follows:
    (A) The thickness at the point of closure of spun cylinders must be 
at least 2 times the prescribed minimum sidewall thickness.
    (B) The thickness of the hemispherical bottoms on cylinders formed 
from sheet or plate must be at least 90 percent of the prescribed 
minimum sidewall thickness.
    (5) Welding or brazing for any purpose is prohibited on cylinders 
manufactured in accordance with this section.
    (6) Plugged cylinders are not authorized.
    (e) Wall thickness. The following requirements apply:
    (1) The minimum wall thickness for a cylinder must be the greater 
of the thickness as determined by this paragraph (e), or as required by 
the individual specification.
    (2) For the minimum wall thickness calculations, the following 
formula must be used:

S = [P(1.3D2+0.4d2)]/
(D2-d2)

Where:

S = Wall stress in Mpa (psi).
P = Minimum test pressure in bar (psi), as prescribed for the 
volumetric expansion test, but not less than 31 bar (450 psi).
D = Outside diameter in mm (inches).
d = Inside diameter in mm (inches).

    (3) A steel cylinder longer than 2 meters (6.5 feet) must meet the 
following additional requirements if the cylinder is horizontally 
supported at its two ends. The load of the cylinder consists of the 
weight per unit length, in newtons per millimeter, of the cylindrical 
portion filled with water and pressurized to the prescribed minimum 
test pressure. The wall thickness must be increased when necessary to 
meet the following requirements:
    (i) The sum of 2 times the maximum tensile stress at the mid-point 
of the unsupported length, due to bending (see paragraph (e)(3)(ii) of 
this section), plus the maximum longitudinal stress in the same area, 
due to the hydrostatic pressure (see paragraph (e)(3)(iii) of this 
section), may not exceed 80 percent of the minimum yield strength of 
the steel as determined by the mechanical tests prescribed in 
Sec. 178.69(i)(7) and the applicable individual specification.
    (ii) The following formula must be used to calculate the maximum 
tensile stress due to bending--

S = MC/I

Where:

S = tensile stress in MPa.
M = bending moment in newton-mm = .125Wl2.
C=radius (D/2) of cylinder in mm.
I=Moment of inertia=.04909 (D4-d4) in 
mm4.
W=weight in newtons per mm of cylinder length full of water.
l=length of cylinder in mm.
D=outside diameter in mm.
d=inside diameter in mm.
    (iii) The following formula must be used to calculate the maximum 
longitudinal tensile stress due to volumetric expansion test pressure--

S(MPa)=[A1P/10A2]
Where:

S=tensile strength in MPa.
A1=internal area in cross section of the cylinder in 
mm2.

A2=area of metal in cross section of the cylinder in 
mm2.
P=volumetric expansion test pressure in bar.

    (f) Openings. Openings are not permitted on the side wall and must 
be centered on the heads. Openings may not exceed the smaller of one-
half of the cylinder's outside diameter or 200 mm (8 inches). All 
openings must be circular and threaded.
    (g) Heat treatment. After forming, cylinders must be uniformly and 
properly heat treated under similar conditions of time, temperature, 
cooling rate and atmosphere prior to all tests. The furnace temperature 
must be controlled to assure a uniform process and have sufficient 
instrumentation to control performance.
    56. Section 178.71 would be added to Subpart C to read as follows:


Sec. 178.71  Specification 3M; seamless steel, nickel and stainless 
steel metric-marked cylinders.

    (a) General requirements and test pressure. Each DOT specification 
3M cylinder must meet the general requirements contained in 
Secs. 178.69 and 178.70 and the specific requirements contained in this 
section. The design test pressure must be no less than 15 bar (218 
psi).
    (b) Duties of the inspector. In addition to the duties prescribed 
in Sec. 178.69(e), an inspector must verify that the grain size in a 3M 
cylinder manufactured from nickel is in accordance with paragraph 
(h)(6) of this section.
    (c) Authorized materials and identification of materials. Materials 
must be in accordance with the following:
    (1) All tubing, billet, sheet, plate or cast stock must be in 
conformance with

[[Page 58499]]

Grade A, C, or D material specified in Table 1 of Appendix A of this 
subpart.
    (i) Grade A material is authorized for steel cylinders.
    (ii) Grade C material is authorized for stainless steel cylinders.
    (iii) Grade D material is authorized for nickel cylinders.
    (d) Manufacture. Spun closures for nickel cylinders are prohibited.
    (e) Wall thickness. (1) For cylinders with a test pressure less 
than 93 bar (1350 psi), the minimum wall must be such that the wall 
stress at the prescribed minimum test pressure does not exceed 165 MPa 
(24,000 psi) for cylinders made from Grade A or C material and in no 
case may the wall thickness be less than 2mm (.078 inch).
    (2) For cylinders with a test pressure of 93 bar (1350 psi) or 
more, the minimum wall must be such that the wall stress at the 
prescribed minimum test pressure does not exceed the following:
    (i) 380 MPa (55,000 psi) for cylinders made from Grade A material;
    (ii) 235 MPa (34,000 psi) for cylinders made from Grade C material.
    (3) For cylinders made from Grade D material, the minimum wall must 
be such that the wall stress at the prescribed minimum test pressure 
does not exceed 100 MPa (15,000 psi), or 50 percent of the minimum 
tensile strength as determined by the mechanical properties tests 
prescribed in Sec. 178.69(i)(7).
    (f) Heat treatment. A cylinder made from:
    (1) Grade A material must be heat treated by normalizing at a metal 
temperature most suitable for the material, and air cooled. Liquid 
quenching is not authorized. Intermediate manganese steel may be given 
a quench and temper heat treatment.
    (2) Grade C material does not require heat treatment.
    (3) Grade D material does not require heat treatment. If the 
cylinder is heat treated, the furnace atmosphere during heat treatment 
must be sulfur-free and neutral or reducing.
    (g) Design qualification tests. The following design qualification 
tests described in Sec. 178.69 apply:
    (1) Cycle test. Cylinders representative of the design must 
withstand, without distortion or failure, at least 10,000 
pressurizations.
    (2) Burst test. Representative cylinders of each design must meet 
the following--
    (i) For nickel cylinders the test cylinders must withstand at least 
2 times test pressure.
    (ii) For steel cylinders the test cylinders must withstand at least 
1.6 times test pressure.
    (h) Production tests and verification. The following examinations 
and tests apply. Unless otherwise noted in this section, acceptable 
results are prescribed in Sec. 178.69.
    (1) Volumetric expansion test.
    (2) Leakage test for spun cylinder.
    (3) Ultrasonic examination in accordance with ASTM E 213 for 
measurement of sidewall defects: Any cylinder having a discontinuity 
greater than two times in length and 10 percent in depth of the 
designed minimum wall thickness or any discontinuity greater than 15% 
of the minimum designed wall thickness in depth must be rejected.
    (4) Mechanical test: The yield strength may not exceed 73 percent 
of the tensile strength for steel cylinders, or 50 percent of the 
tensile strength for nickel cylinders. Elongation must be at least 20 
percent for a 50mm (2-inch) gauge length specimen or at least 10 
percent in other cases. In this instance, a flattening test or bend 
test is required. If elongation is at least 40 percent for the 50mm (2-
inch) gauge length specimen, or at least 20 percent in other cases, a 
flattening test or bend test is not required.
    (5) Flattening or bend test: Steel cylinders must withstand 
flattening to six times wall thickness without cracking; nickel 
cylinders must withstand flattening to four times wall thickness 
without cracking. Bend test specimens must be free of cracking when 
deformed around a mandrel not greater in diameter than 4 times the wall 
thickness for steel or 2 times the wall thickness for nickel.
    (6) Grain size verification: For nickel cylinders, a specimen must 
be taken from the sidewall of a representative cylinder from each lot. 
The diameter of the average grain cross section may not exceed 0.065 mm 
(0.0026 inch). The corresponding ASTM micro-grain size number is 5.0. 
When the grain size in the test cylinder exceeds this limit, the lot 
must be rejected.
    (7) Magnetic particle or liquid penetrant examination: Magnetic 
particle or liquid penetrant inspection must be performed on each 
cylinder constructed of intermediate manganese steel after heat 
treatment to determine the presence of quenching cracks. Cracked 
cylinders must be rejected.
    (i) Rejected cylinders. Nickel cylinders, rejected for unacceptable 
grain size, may be reheat treated. Thereafter, the reheat treated 
cylinders must pass all prescribed tests including verification of 
acceptable grain size.
    57. Section 178.72 would be added to Subpart C to read as follows:


Sec. 178.72  Specification 3ALM; seamless aluminum metric-marked 
cylinders.

    (a) General requirements. Each DOT Specification 3ALM seamless 
aluminum cylinder must meet the general requirements contained in 
Secs. 178.69, 178.70 and the specific requirements contained in this 
section.
    (b) Capacity. The water capacity may not exceed 454 kg (1,000 
pounds).
    (c) Duties of the inspector. In addition to the duties prescribed 
in Sec. 178.69(e), the inspector must verify compliance with the 
provisions in paragraph (d) of this section, either by inspection or by 
obtaining the material manufacturer's certificate of inspection.
    (d) Authorized material and identification of materials. Only the 
aluminum alloy specified in Table 2 of Appendix A to this subpart is 
authorized. Material must be identified with the heat or cast code by a 
suitable method that will identify the alloy. Cast stock must have 
uniform isotropic grain structure not to exceed 500 microns maximum.
    (e) Manufacture. Only the extrusion process is authorized. Closures 
formed by spinning are prohibited. The cylinder bottom must be concave 
to pressure. The thickness of the cylinder base may not be less than 
the side wall thickness. The bottom of the cylinder must have an inside 
shape that is torispherical, hemispherical or ellipsoidal, where the 
dish radius is no greater than 1.2 times the inside diameter of the 
shell. The knuckle radius may not be less than 12 percent of the inside 
diameter of the shell. The interior base contour may deviate from the 
true torispherical, hemispherical or ellipsoidal configuration, 
provided that--
    (1) Any area of deviation is accompanied by an increase in base 
thickness;
    (2) All radii of merging surfaces are equal to or greater than the 
knuckle radius; and
    (3) Each design has been qualified by successfully passing the 
cycling and burst tests specified in paragraph (h) of this section.
    (f) Wall thickness. The minimum wall thickness must be such that 
the wall stress at the prescribed minimum test pressure does not exceed 
80 percent of the minimum yield strength nor 67 percent of the minimum 
tensile strength of the cylinder material as determined by the 
mechanical properties tests prescribed in Sec. 178.69(i)(7), but in no 
case may the minimum wall thickness be less than 4mm (0.156 inch).

[[Page 58500]]

    (g) Heat treatment. Prior to any test, each cylinder must be 
subjected to a solution heat treatment and aging treatment appropriate 
for the type of aluminum used.
    (h) Design qualification tests. The following design qualification 
tests described in Sec. 178.69 apply:
    (1) Cycle test. Cylinders representative of the design must 
withstand, without distortion or failure, at least 10,000 
pressurizations to the prescribed minimum test pressure.
    (2) Burst test. Cylinders representative of the design, must have a 
minimum burst of 1.6 times test pressure.
    (i) Production tests and verifications. The following examinations 
and tests apply. Unless otherwise noted in this section, acceptable 
results are prescribed in Sec. 178.69.
    (1) Volumetric expansion test.
    (2) Ultrasonic examination. The examination must be performed in 
accordance with ASTM E 213 for measurement of sidewall defects. Any 
cylinder having a discontinuity greater than two times in length and 5 
percent in depth of the design minimum wall thickness must be rejected.
    (3) Mechanical tests. Mechanical tests must be performed as 
follows: The two tensile specimens must be one of the following: Flat 
specimen, 50 mm (2-inch) gauge length; Flat specimen, 24t gauge length 
by 6t width; or Round specimen, 4D gauge length with diameter ``D''. 
When the cylinder sidewall is greater than 5 mm (\3/16\-inch), a retest 
without reheat treatment using this ``4D'' specimen is authorized if 
the test using the 2-inch specimen fails to meet elongation 
requirements. The 4D specimen must meet requirements of ASTM E 8. 
Tensile strength must be at least 260 Mpa (38000 psi). Yield strength 
must be at least 240 Mpa (35,000 psi). Elongation must be at least 14 
percent for 50 mm (2-inch) gauge length specimen, at least 10 percent 
for 24t by 6t specimen, and at least 14 percent for the ``4D'' 
specimen.
    (4) Flattening and bend test. A flattening or bend test must be 
performed as follows:
    (i) The flattening test must be performed by placing the test 
cylinder between wedge-shaped knife edges having a 60 degree included 
angle, and rounded in accordance with the following table. The 
longitudinal axis of the cylinders must be at an angle of 90 degrees to 
the knife edges during the test. The test cylinder must withstand 
flattening to 9 times wall thickness without cracking. The table 
follows:

                         Table.--Flattening Test
------------------------------------------------------------------------
                                                               Rounded
            Cylinder wall thicknesses  (inches)                 radius
                                                               (inches)
------------------------------------------------------------------------
Under 0.150................................................        0.500
0.150 to 0.249.............................................        0.875
0.250 to 0.349.............................................        1.500
0.350 to 0.449.............................................        2.125
0.450 to 0.549.............................................        2.750
0.550 to 0.649.............................................        3.500
0.650 to 0.749.............................................        4.125
------------------------------------------------------------------------

    (ii) An alternate bend test, in accordance with ASTM E 290 using a 
mandrel diameter not more than 6 times the wall thickness, is 
authorized. This test may be used to qualify a lot that has failed the 
flattening test. Reheat treatment is not required for this test. If 
used, this test must be performed on 2 samples from one cylinder taken 
at random out of each production lot. The test specimens shall remain 
uncracked when bent inward around a mandrel in the direction of 
curvature of the cylinder wall, until the interior edges are at a 
distance apart not greater than the diameter of the mandrel.
    58. Section 178.73 would be added to Subpart C to read as follows:


Sec. 178.73  Specification for DOT 3FM; seamless steel metric-marked 
cylinders.

    The construction of a cylinder to this specification also meets the 
requirement of draft ISO 9809-2, Transportation of Seamless Steel Gas 
Cylinders--Design Construction and Testing--Part 2: Quenched and 
Tempered Steel with Tensile Strength Greater Than or Equal to 1100 MPa.
    (a) General requirements and definitions. Each Specification DOT 
3FM seamless steel cylinder must meet the general requirements 
contained in Secs. 178.69, 178.70 and the specific requirements 
contained in this section.
    (b) Authorized material and identification of materials. All 
tubing, billet or cast stock must conform to Grade B or Grade E 
material specified in Table 1 of Appendix A of this subpart.
    (c) Manufacture. Closures formed by spinning are prohibited.
    (d) Wall thickness. The minimum wall thickness must be such that 
the wall stress at the prescribed minimum test pressure does not exceed 
the lesser of 483 Mpa (70,000 psi) for Grade B material or 624 MPa 
(90,500 psi) for Grade E material, or 67 percent of the minimum tensile 
strength as determined from the mechanical properties tests prescribed 
in paragraph 178.69(i)(7), but in no case may the minimum wall 
thickness be less than 1.5 mm (.058 inch).
    (e) Heat treatment. Each cylinder must be suitably quench and 
temper heat treated and held at that temperature for a suitable period 
of time. Each cylinder must then be air cooled under conditions 
recommended for the steel. The minimum tempering temperature of the 
metal must be at least 570  deg.C (1058  deg.F).
    (f) Design qualification tests. The following design qualification 
tests described in Sec. 178.69 apply:
    (1) Cycle test. Cylinders representative of the design must 
withstand, without distortion or failure, at least 10,000 
pressurizations to the prescribed minimum test pressure.
    (2) Burst test. Cylinders representative of the design, must have a 
minimum burst of 1.6 times the marked test pressure.
    (g) Production tests and verifications: The following examinations 
and tests apply. Unless otherwise noted in this section, acceptable 
results are prescribed in Sec. 178.69.
    (1) Volumetric expansion test.
    (2) Ultrasonic examination. The examination must be performed in 
accordance with ASTM E 213 for the measurement of sidewall defects. Any 
cylinder having a discontinuity greater than 24 mm (1 inch) in length 
and a depth greater than 5 percent of the design minimum wall thickness 
must be rejected.
    (3) Hardness test. A hardness test must be performed on the 
cylindrical section of each cylinder after heat treatment. The tensile 
strength equivalent of the hardness number obtained from the test may 
not be more than 1,140 MPa (166,000 psi). The hardness number may not 
exceed 37 HRC or 344 HBS. If the hardness number is exceeded, then the 
lot must be rejected.
    (4) Mechanical tests. (i) Specimen size must be gauge length 50 mm 
(2 inches) and a maximum width of 38 mm (1.5 inches). For cylinders 
over 454 kg (1,000 pounds) water capacity, specimens may be the 
Standard Round Tension Specimen as specified in ASTM A-370 (0.357 
inches minimum diameter).
    (ii) Elongation must be at least 16 percent for the 50 mm (2 
inches) gauge length specimen. Tensile strength may not exceed 1,069 
MPa (155,000 psi). For round specimens, the minimum elongation must be 
at least 15 percent.
    (5) Impact tests. (i) Three specimens must be impact tested per 
lot. Each specimen must be taken from the sidewall of the cylinder or 
test ring. The axis of the specimen must be perpendicular to the 
longitudinal axis of the cylinder, with the axis of the notch in the 
``T-L'' orientation as illustrated in figure 3 of ASTM E 399. Each 
specimen must be Charpy V-Notch type, size 10

[[Page 58501]]

mm (.40 inch)  x 5 mm (.20 inch) or 4 mm (.16 inch).
    (ii) For cylinders over 454 kg (1,000 pounds) water capacity, the 
axis of the specimen must be parallel to the longitudinal axis of the 
cylinder, with the axis of the notch in the ``L-C'' orientation as 
illustrated in figure 3 in ASTM E 399. Each specimen must be Charpy V-
Notch type, size 10 mm (.40 inch)  x 10 mm (.40 inch) if cylinder 
thickness permits. When only a reduced size specimen can be obtained, 
it must be the largest standard size obtainable but not smaller than 10 
mm (.40 inch)  x 5 mm (.20 inch).
    (iii) For cylinders constructed of Grade E material, the Charpy V-
Notch impact properties for the three specimens must be tested at minus 
50 deg.C (minus 60 deg.F), or colder; and the values obtained may be 
not less than the values shown in the following table. For cylinders 
constructed of Grade B material, the Charpy V-Notch impact properties 
for the three specimens must be tested at minus 50 deg.C (minus 
60 deg.F ), or colder; and the values obtained must not be less than 
the values shown in the following table:

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                           Average value for acceptance    Minimum value for acceptance
                                                                                                  for 3 specimens         for one specimen only of the 3
                                                       Size of specimen (mm)             --------------------------------            specimens
                                                                                                                         -------------------------------
                                                                                              (ft-lb)         (j/cm2)         (ft-lb)         (j/cm2)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Grade B
                                           10.0  x  10.0................................              25              42              20              34
                                           10.0  x  7.5.................................              21              48              17              39
                                           10.0  x  5.0.................................              17              58              14              47
Grade E
                                           10.0  x  5.0.................................              15              50              12              40
                                           10.0  x  4.0.................................              12              40             9.5              32
--------------------------------------------------------------------------------------------------------------------------------------------------------

    59. Section 178.81 would be added to Subpart C to read as follows:


Sec. 178.81  Specification for DOT 4M; Welded metric-marked cylinders.

    (a) General. DOT specification 4M cylinders must meet the 
requirements contained in this section and Sec. 178.69.
    (1) The design test pressure for DOT specification 4M cylinders 
must be less than or equal to 140 bar (2030 psi).
    (2) [Reserved]
    (b) Lot size. For cylinders manufactured under the provisions of 
this section, in no case may a lot size exceed 500.
    (c) Authorized materials and identification of materials. For an 
aluminum cylinder only Aluminum Association alloy 5154 is authorized. 
For a steel cylinder, stock must conform to a material listed in Table 
1 as follows:

[[Page 58502]]

[GRAPHIC] [TIFF OMITTED] TP30OC98.001



[[Page 58503]]

    (d) Manufacture. (1) A DOT-4M specification cylinder must be 
manufactured only by a process specifically authorized by and conform 
to the applicable requirements of this section.
    (2) The manufacturing process must produce cylinders that are free 
of defects which are likely to weaken the finished cylinder. Heads must 
be seamless, hemispherical or ellipsoidal in shape with the major 
diameter not more than two times the minor diameter, or a dished shape 
falling within these limits. For heads concave to pressure, the minimum 
head thickness may not be less than 90 percent of the required 
thickness of the sidewall. For heads convex to pressure, the minimum 
thickness must be not less than two times the required thickness of the 
sidewall. The bottom thicknesses must be measured within an area 
bounded by a line representing the points of contact between the 
cylinder and floor when the cylinder is in a vertical position. For 
cylinders with a wall thickness less than 2.5 mm (0.100 inch), the 
ratio of tangential length to outside diameter may not exceed 4.0.
    (3) Welding processes and machine operators shall meet 
qualification standards and comply with operating procedures specified 
in CGA Pamphlet C-3.
    (i) Circumferential seams must be butt welded with one member 
offset (joggle butt) or lapped with minimum overlap of at least four 
times wall thickness. Other butt joints must be authorized in writing 
by the Associate Administrator. Fillet weld beads must be flat or 
convex and the leg of any fillet weld subjected to shear stress must be 
at least 1.3 times the shell wall thickness. For spheres, the maximum 
joint efficiency for design calculations is 0.85. Heat affected zones 
are considered to extend a distance of six times the wall thickness 
from the center line of the weld.
    (ii) Longitudinal seams must have complete penetration, and must be 
free from undercuts, overlaps or abrupt ridges or valleys. Misalignment 
of mating butt edges must not exceed 0.166 of the wall thickness or 0.8 
mm (0.031-inch), whichever is less. For cylinders with nominal wall 
thickness up to and including 3.2 mm (0.125 inch), joints must be 
tightly butted. When wall thickness is greater than 3.2 mm (0.125 
inch), the joint must be gapped with maximum distance equal to one-half 
the wall thickness or 0.8 mm (0.031 inch) whichever is less.
    (iii) The joint efficiency is 1.0, .90 or .75, as appropriate, for 
welded joint described in paragraph (i)(6) of this section.
    (iv) The tensile strength of welded joints must be equal to or 
greater than the minimum required tensile strength of the shell 
material of the finished cylinder.
    (v) Attachments may not be welded to the sidewall of the cylinder. 
Welding of attachments must be completed prior to all pressure tests 
and prior to heat treatment when required. Attachments must be made of 
weldable material of an alloy which is compatible with the cylinder. 
The carbon content for steel attachments may not exceed 0.25 percent.
    (e) Wall thickness. The minimum wall thickness of a DOT 4M cylinder 
must be the greater of the thickness as determined by the following 
criteria:
    (1) The minimum wall thickness for a carbon steel, HSLA steel or 
stainless steel cylinder with an outside diameter greater than 127 mm 
(5 inches) must be 2.0 mm (0.078 inch) and for an aluminum cylinder 
with an outside diameter greater than 127 mm (5 inches) must be 4 mm 
(0.156 inch).
    (2) The minimum wall thickness for a carbon steel, HSLA steel or 
stainless steel cylinder with an outside diameter less than or equal to 
127 mm (5 inches) must be 1.5 mm (.058 inch) and for an aluminum 
cylinder 2.5 mm (0.097 inch).
    (3) Each cylinder must have a wall thickness such that the wall 
stress calculated at test pressure using the formula listed in 
paragraph (e)(4)(i) and (ii) of this section may not exceed the 
following allowable stresses at test pressure:
    (i) For DOT 4M cylinders made from HSLA steel, 260 Mpa (37,000 
psi).
    (ii) For DOT 4M cylinders made from carbon steel, 165 Mpa (24,000 
psi).
    (iii) For DOT 4M cylinders made from aluminum alloy 5154, 138 Mpa 
(20,000 psi).
    (iv) For DOT 4M cylinders made from 4130X steel, 255 Mpa (70,000 
psi).
    (v) For DOT 4M cylinders made from stainless steel cylinders, 410 
Mpa (60,000 psi).
    (4) For minimum wall thickness calculations, one of the following 
formula must be used:
    (i) For cylinders that are cylindrical in shape:

S(MPa) = (P(1.3D\2\ + .4d\2\))/E(10(D\2\-d\2\))

Where:

S = Wall stress in MPa.
P = Minimum test pressure in bar, as prescribed for the hydrostatic 
test.
D = Outside diameter in mm.
d = Inside diameter in mm.
E = Joint efficiency of the longitudinal seam.

    (ii) For cylinders that are spherical in shape:

S(MPa) = PD / 40tE

Where:

S = wall stress in MPa.
P = Minimum prescribed test pressure in bar.
D = Outside diameter in mm.
t = Minimum wall thickness in mm.
E = weld efficiency factor.

    (f) Openings. Openings must conform to the following:
    (1) Openings are permitted in heads only. The opening must be 
circular or elliptical.
    (2) Openings must be provided with adequate fittings, bosses or 
pads, integral with or securely attached to the cylinder by welding. 
Each fitting, boss or pad must be compatible with the cylinder 
material. Method of attachment must be the same as the method of 
construction.
    (3) When more than one opening exists in the head or bottom of the 
cylinder, these openings must be separated by ligaments of at least 
three times the average of their hole diameters.
    (g) Heat treatment. When a completed cylinder is required to be 
heat treated, each cylinder in a lot must be uniformly and properly 
heat treated under similar conditions of time, temperature, cooling 
rate and atmosphere prior to all tests. The furnace temperature for 
heat treatment must be controlled on a continuous basis by use of 
automated instrumentation to control performance.
    (1) Heat treatment must follow all forming and welding operations.
    (2) Each completed cylinder must be heat treated, as follows:
    (i) Quench and temper heat treatment is authorized only for a DOT 
4M cylinder made from 4130X steel.
    (A) Tempering must be accomplished by reheating the quenched 
cylinder to a temperature below the transformation range, and holding 
at that temperature for at least one hour per 25 mm (1 inch) of 
thickness, based on the shell thickness of the cylinder. Each cylinder 
must then be air cooled under uniform conditions.
    (B) The tempering temperature of the 4130X steel must be at least 
538  deg.C (1000  deg.F).
    (ii) Stress relieving heat treatment for HSLA steel and carbon 
steel cylinders must be at a temperature of at least 593  deg.C (1100 
deg.F).
    (iii) Normalizing heat treatment for HSLA steel and carbon steel 
cylinders must be at a temperature of at least 870  deg.C (1600 
deg.F).
    (iv) Heat treatment is not required for a stainless steel.
    (v) For an aluminum alloy 5154 cylinder, heat treatment is not 
required.

[[Page 58504]]

    (h) Design qualification tests. The following design qualification 
test described in Sec. 178.69 apply. Burst test: five representative 
cylinders of each design, or any significant change to a previously 
tested design, must be burst tested. Each test cylinder must achieve 
the minimum burst pressure as specified in Table 2 of paragraph (i) of 
this section without leakage or rupture.
    (i) Production tests. The following examinations and tests apply. 
Unless otherwise noted in this section, procedures and acceptable 
results are prescribed in Sec. 178.69.
    (1) Pressure test. Pressure testing must conform to the frequency, 
schedules and pressures as specified in Table 2 of this paragraph (i).
    (2) Leak test. Each fully assembled cylinder must be subjected to a 
gas leakage test, using a dry inert gas, at one half the design test 
pressure while the cylinder is immersed in water, by coating it with a 
leak detecting solution, or by an alternate test method approved by the 
Associate Administrator. Table 2 follows:

                                                                         Table 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Volumetric \1\ expansion test
                                                    ---------------------------------------------------
             DOT spec.                  Lot size                                            Maximum       Proof test pressure \3\       Minimum burst
                                                             Test pressure(TP)          permitted PVE/                                   pressure \4\
                                                                                            TVE \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
4M \5\.............................             500  As marked........................             10%  @ TP.......................  2 x TP
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ At least one cylinder per lot must be subjected to volumetric expansion test. If each cylinder is subjected to the volumetric expansion test the
  proof test is not required.
\2\ PVE = permanent volumetric expansion; TVE = total volumetric expansion.
\3\ Each cylinder must be proof tested at the TP.
\4\ One cylinder per lot must be pressurized to destruction; minimum burst is expressed in multiples of TP.
\5\ See Secs.  173.302b and 173.304b of this subchapter for fill (service) pressure of DOT 4M cylinders.

    (3) Mechanical tests. Mechanical tests must be taken from a minimum 
of two sample cylinders per lot selected at random after pressure test 
and heat treatment, if required. Test specimens must be taken as 
depicted in figures 1 through 5 of Appendix C of this subpart for the 
specific design utilized for construction.
    (i) For cylinders and spherical shapes which are not of sufficient 
size to secure test specimens, an alternate testing protocol must be 
approved in writing by the Associate Administrator.
    (ii) A test cylinder need represent only one of the heats of 
material of construction in the lot, provided that other heats in the 
lot have been tested and passed when heat treated under similar 
conditions.
    (iii) If, due to welded attachments on the heads, there is 
insufficient surface from which to take specimens, specimens may be 
taken from a cylinder prepared as a test cylinder which does not have 
the attachments but is the same as the other cylinders in the lot and 
is heat treated with the lot it represents.
    (iv) Minimum elongations are specified in Table 3 or Table 4 of 
this paragraph (i), as appropriate.
    (v) Acceptable results. The yield strength may not exceed 73 
percent of tensile strength for carbon steel and 80 percent of tensile 
strength for aluminum alloy 5154.
    (4) Flattening test. A flattening test must be performed on a test 
cylinder selected from each lot. Cylinders must be flattened, without 
cracking, between knife edges as specified in Sec. 178.69(i)(1) to six 
times the wall thickness for steel cylinders and ten times the wall 
thickness for aluminum cylinders. The minimum distance is to be 
measured between the knife edges or plates while the specimens are 
under compression. For spherical shapes, flattening is to be performed 
on a press, between parallel steel plates with the welded seam at right 
angles to the plates. Alternatively, a test ring cut from the sphere 
which includes the weldment and at least one inch of material on each 
side may be crushed between parallel steel plates with welded seam at 
right angles to the plates. Any projecting appurtenances may be removed 
prior to flattening. Removal must not produce a temperature exceeding 
204  deg.C (400  deg.F).
    (5) Burst test. For production testing one cylinder selected at 
random from each lot must be burst tested. Each test cylinder must 
achieve the minimum burst pressure as specified in Table 2 of this 
paragraph (i) without leakage or rupture.
    (6) Joint efficiency. (i) The joint efficiency is 1.0 when all weld 
seams, both longitudinal and circumferential, are completely 
radiographically examined and defects removed. Weld repair areas must 
be reinspected to confirm that defects have been removed and the 
repaired area is of acceptable weld quality.
    (ii) The joint efficiency is 0.90 when one cylinder from the first 
10 production cylinders and one cylinder from each 100 consecutively 
welded cylinders thereafter are completely radiographically examined 
and show no defects. When defects are found in the sample cylinder all 
cylinders welded since the last acceptable sampling must be inspected 
completely and defects removed and repaired. When welding operations 
are suspended for more than four hours one cylinder must be inspected 
completely from the first 10 production cylinders after resumption of 
welding.
    (iii) The joint efficiency is 0.75 when there is no radiographic 
weld examination.
    (iv) A cylinder which is less than 21.4 kg (48 lbs) water capacity 
and test pressure less than 34.5 bar (500 psig) manufactured to a two 
piece design has a joint efficiency of 1.0 and requires no radiographic 
examination.
    (v) Radiographic examination is required for DOT 4M cylinders 
constructed from 4130X steel and all DOT 4M cylinders with design test 
pressure equal to or greater than 70 bar (1015 psi). Radiographic 
examination must be performed on all welded joints which are subjected 
to internal pressure.
    (vi) As an alternative to radiographic examination, an ultrasonic 
examination may be used in accordance with Appendix B of this subpart.
    (7) Mechanical test of welds. Tests must be performed on specimens 
taken, as illustrated in Figure 1 through 5 of Appendix C of this 
subpart, from a cylinder chosen at random from each lot. Acceptable 
results:
    (i) Tensile test results must meet acceptance criteria specified in 
CGA Pamphlet C-3 with specimen failure at a stress of not less than two 
times the wall stress at test pressure, calculated using the actual 
wall thickness.
    (ii) Guided bend test results must meet acceptance criteria 
specified in CGA Pamphlet C-3.

[[Page 58505]]

    (iii) Alternate guided bend test results must meet acceptance 
criteria specified in CGA Pamphlet C-3 and Sec. 178.69(i)(8)(iii). 
Tables 3 and 4 follow:

                                              Table 3.--Elongation
----------------------------------------------------------------------------------------------------------------
                                                                          Minimum elongation (in percent)
                                                                 -----------------------------------------------
                                                                   Gauge length    Gauge length
                                                                   x  width ((50   x  width \1\
                            Material                               mm x 38 mm)(2    38     of 24t  x
                                                                  inch x 1.5 inch))  1.5        6t
                                                                                      inch))
----------------------------------------------------------------------------------------------------------------
Aluminum, alloy 5154............................................              12              12              12
Steel (tensile strength <3447 MPA (50,000 psi)).................              40              20             20
----------------------------------------------------------------------------------------------------------------
Note 1: A gauge length of at least 24 times shell thickness and a width of not greater than six times shell
  thickness is authorized when cylinder wall is not greater than 4.7 mm (0.188 inch) thick.


                                     Table 4.--Alternate Minimum Elongation
----------------------------------------------------------------------------------------------------------------
                                    Alternate minimum elongation (in percent)
-----------------------------------------------------------------------------------------------------------------
                     Shell tensile strength                       Having tensile strength >3447 MPA (50,000 psi)
----------------------------------------------------------------------------------------------------------------
                                                                   Gauge length
                                                                   x  width ((50   Gauge length
                                                                  mm  x  38 mm) (2     ((200 mm  x    Gauge length
                  MPA                              PSI             inch  x  38     of 24t  x
                                                                    thn-eq>1.5     mm)(8 inch  x  width\1\ of 6t
                                                                      inch))      1.5
                                                                                      inch))
----------------------------------------------------------------------------------------------------------------
3964.......................  57500........              38              19              19
4482.......................  65000........              36              18              18
5000.......................  72500........              34              17              17
5520.......................  80000........              32              16             16
----------------------------------------------------------------------------------------------------------------
Note 1: A gauge length of at least 24 times shell thickness and a width of not greater than six times shell
  thickness is authorized when cylinder wall is not greater than 4.7 mm (0.188 inch) thick.

    (j) [Reserved]
    (k) Cylinder Rejection. Each test cylinder or each lot represented 
by a test cylinder that does not meet the acceptable test results must 
be rejected. When a lot of cylinders is rejected, due to failure of the 
mechanical, flattening, or weld test, the lot may be reheat treated and 
retested as if it were a new lot. Reheat treatment is limited to two 
times.
    (l) Leakage test. A spun cylinder rejected under paragraph (i)(2) 
of this section must be scrapped, condemned or rendered incapable of 
holding pressure.
    (m) Repairs. A repair of weld seams is authorized using the same 
process as that used for the original welding. A rewelded cylinder must 
be reheat treated and pass all prescribed tests.
    60. Appendices A, B and C would be added to Subpart C of Part 178 
to read as follows:

Appendix A to Subpart C of Part 178--Specifications for Steel, 
Nickel and Aluminum

                                    Table 1.--Steel and Nickel--Heat Analysis--Chemical Composition in Weight Percent
              [For grades A-E, incidental elements to be within the limits specified in the AISI Manual 1for Semifinished Steel Products.]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                   B  min/
    Grade       Type of material    C  min/max  Mn  min/max   P  max   S  max  Si  min/max  Cr  min/max  Mo  min/max  Ni  min/max    max         Fe
--------------------------------------------------------------------------------------------------------------------------------------------------------
A...........  Carbon \3\             0.10/0.50      --/1.75    0.035    0.025      --/0.30  ...........  ...........  ...........  .......  Bal.
               Manganese.
B...........  Chrome Moly Type...    0.25/0.50    0.40/1.05    0.035    0.025    0.15/0.35    0.80/1.15    0.15/0.25  ...........  .......  Bal.
C...........  Stainless \2\......     --/0.080      --/2.00    0.035    0.030      --/1.00    16.0/20.0    2.00/3.00     8.0/15.0  .......  Bal.
D...........  Nickel.............  ...........  ...........  .......  .......  ...........  ...........  ...........      99.0/--  .......  Bal.
E...........  Chrome \4\ Moly        0.32/0.38    0.60/1.05    0.015    0.010    0.15/0.35    0.80/1.15    0.15/0.25  ...........  .......  Bal.
               Type.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The AISI manual referenced in the heading means ``American Iron and Steel Institute'' Steel Products Manual--Alloy, Carbon, and High Strength Low
  alloy Steels; Semifinished: dated March 1986.
\2\ The minimum for molybdenum (2.00) shown, applies only to Stainless Steel type 316.
\3\ Forging or drawing quality steel required; rimmed steel not authorized.
\4\ Forging or drawing quality steel required; produced to predominantly fine grain practice.


   Table 2.--Aluminum--Heat or Cast Analysis for Aluminum; Similar to ``Aluminum Association'' \1\ Alloy 6061 Chemical Analysis in Weight Percent \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                Other
                                                                                                         ------------------
Si  min/max  Fe  max  Cu  min/max  Mn  max  Mg  min/max  Cr  min/max  Zn  max  Ti  max  Pb  max  Bi  max    Each    Total                Al
                                                                                                            max      max
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.40/0.80..     0.70    0.15/0.40     0.15    0.80/1.20    0.04/0.35     0.25     0.15    0.005    0.005     0.05     0.15  Bal.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The ``Aluminum Association'' refers to ``Aluminum Standards and Data 1993'', published by the Aluminum Association Inc.

[[Page 58506]]

\2\ Except for ``Pb'' and ``Bi'', the chemical composition corresponds with that of Table 1 of ASTM B221M for Aluminum Association alloy 6061.


                          Mechanical Properties
    [Aluminum in conformance with the specification in Table 2 above,
                   thermally treated to ``T6'' temper]
------------------------------------------------------------------------
                                                    Elongation, percent
    Tensile strength      Yield strength minimum  minimum, for 2 inch or
   minimum (Mpa) \1\            (Mpa) \1\          4D \2\ size specimen
------------------------------------------------------------------------
262....................                241                  14 \3\
------------------------------------------------------------------------
\1\ MPA x 145 = psi.
\2\ ``D'' represents specimen diameter. When the cylinder is over 3/16
  inch thick, a retest without reheat treatment, using the 4D specimens
  is authorized, if the test using the 2 inch size specimen fails to
  meet elongation requirements.
\3\ ``10 percent'' minimum elongation is authorized, when using a 24t x
  6t test specimen if the cylinder sidewall is not over 3/16 inch thick.

Appendix B To Subpart C of Part 178--Ultrasonic Examination of 
Cylinders

    Ultrasonic examination (UT) includes straight beam pulse echo 
testing that measures 100 percent of the cylinder's sidewall 
thickness and angle beam (shear wave) pulse echo that identifies and 
measures cracks, pits, laminations, laps, and other defects.
    a. UT equipment. The UT equipment shall consist of a pulse-echo 
test instrument that is capable at a minimum, of generating, 
receiving, and presenting high energy pulses in an A-scan 
presentation on a display. It must have a minimum frequency of 1.0 
MHZ and a minimum frequency range of 1.0 to 5.0 MHZ.
    1. The UT equipment must continually monitor the acoustic 
coupling to assure 100% cylinder sidewall coverage during the 
testing and automatically terminate the testing if the coupling is 
lost. The equipment also must be capable of providing a linear 
presentation of crack depth. The equipment calibration must be 
verified for each type of cylinder to be examined using the 
calibration standard in paragraph b of this Appendix prior to 
testing. At a minimum, the equipment calibration must be verified at 
the beginning of each work shift, not to exceed 10 continuous hours.
    2. The UT equipment must have multiple focused array transducers 
to perform both straight beam and angle beam testing of the cylinder 
sidewall and sidewall to base transition. A straight-beam search 
unit consists of a piezoelectric crystal mounted to a fixture that 
is perpendicular to the longitudinal axis of the cylinder. A shear 
wave search unit consists of piezoelectric crystals mounted to a 
fixture that are angled at 45 deg. or 60 deg. to the longitudinal 
axis of the cylinder sidewall. The frequency and angle of each 
search unit must be determined during calibration based on material, 
diameter, and wall thickness of the cylinder. A proper search unit 
must be selected to obtain a good resolution and a minimum accuracy 
of +/-5% of the defect depth. A search unit frequency of 2.25 MHZ to 
10.0 MHZ must be used. The equipment used must be calibrated to 
detect a discontinuity 25.4 mm (1 inch) in length and a depth of 5 
percent of the prescribed minimum wall thickness.
    b. Calibration standard. A cylinder used as a calibration 
standard must be of the same diameter (+/-10%), surface finish, 
metallurgical type, and specification as the cylinders to be tested, 
for example, a DOT 3FM calibrated cylinder must be used for 3FM 
cylinders. The calibration cylinder must be machined with features 
that simulate defects such as pits, fatigue cracks, and reduced wall 
thickness. The size of the defect feature shall be approximately the 
same as the applicable pass-fail criteria identified in Table II of 
Sec. 180.207 of this subchapter for requalification of metric-marked 
cylinders, as identified in Table II of Sec. 180.209 of this 
subchapter for requalification of nonmetric-marked cylinders or as 
identified in the applicable cylinder specification. The minimum 
wall thickness and defect sizes in the calibration cylinder must be 
confirmed by mechanical measurements and certified by a non-
destructive testing (NDT) Level III in UT. The size of the defect 
features in the calibration cylinder shall be measured every five 
years to confirm that the defect sizes have not been changed. A 
certification statement signed by a person certified to NDT Level 
III in UT must be maintained for each calibration standard and made 
available for review, upon request, by an authorized RSPA 
representative.
    c. Couplant. The same couplant must be used for both calibration 
and actual testing.
    d. UT procedure and reporting requirements. The UT procedure and 
reporting requirements used must be in accordance with ASTM E 797 
for wall thickness measurement and ASTM E 213 for sidewall defect 
measurement. The UT program must be approved in writing by the 
Associate Administrator.
    1. The surface of the cylinder to be inspected shall be free of 
extraneous loose material such as scale, loose paint, and dirt.
    2. The rotational speed of the cylinder under examination may 
not exceed the rotational speed used during calibration.
    3. The UT results must be evaluated in accordance with pass-fail 
criteria identified in Table II of Sec. 180.207 of this subchapter 
for requalification of metric-marked cylinders, as identified in 
Table II of Sec. 180.209 of this subchapter for requalification of 
nonmetric-marked cylinders or as identified in the applicable 
cylinder specification.
    e. Personnel Qualifications and Responsibilities: Each facility 
where testing is to be performed must be under the managerial 
direction of a Senior Review Technologist (SRT).
    1. The SRT must define the overall test program, provide 
supervisory training and technical guidance to operators, review and 
certify test results and maintain proof of qualifications for each 
``qualified tester''. The SRT must have a Level III, UT 
Certification, in accordance with the ASNT Recommended Practice SNT-
TC-1A and a thorough understanding of this subchapter pertaining to 
the qualification and use of DOT cylinders.
    2. The person performing cylinder testing, the ``qualified 
tester'', must be at a minimum a qualified Level II, UT in 
accordance with ASNT-TC-1A. The ``qualified tester'' may perform 
system startup, calibrate the system, and review and validate the 
test results.
    3. A person with Level I certification may perform a system 
startup, check calibration, and perform UT only under the direct 
guidance, supervision, and observation of a Level II or Level III 
Operator.
    4. Each ``qualified tester'' must have written procedures for 
conducting UT, for operation of equipment, a copy of this 
subchapter, proof of qualifications, and records of all tests 
performed at the facility where testing is performed.

[[Page 58507]]

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[[Page 58508]]

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[[Page 58509]]

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[[Page 58510]]

[GRAPHIC] [TIFF OMITTED] TP30OC98.005



[[Page 58511]]

[GRAPHIC] [TIFF OMITTED] TP30OC98.006



BILLING CODE 4910-60-C

[[Page 58512]]

PART 180--CONTINUING QUALIFICATION AND MAINTENANCE OF PACKAGINGS

    61. The authority citation for Part 180 would continue to read as 
follows:

    Authority: 49 U.S.C. 5101-5127; 49 CFR 1.53.

    62. Subpart C would be added to Part 180 to read as follows:

Subpart C--Qualification, Maintenance and Use of Cylinders

Sec.
180.201  Applicability.
180.203  Definitions.
180.205  General requirements for requalification of cylinders.
180.207  Requirements for requalification of metric-marked 
specification cylinders.
180.209  Requirements for requalification of nonmetric-marked 
specification cylinders.
180.211  Repair, rebuilding and reheat treatment of nonmetric-marked 
DOT-4 series specification cylinders.
180.213  Requalification markings.
180.215  Reporting and record retention requirements.

Subpart C--Qualification, Maintenance and Use of Cylinders


Sec. 180.201  Applicability.

    This subpart prescribes requirements, in addition to those 
contained in Parts 107, 171, 172, 173 and 178 of this chapter, 
applicable to any person responsible for the continuing qualification, 
maintenance, or periodic requalification of DOT specification and 
exemption cylinders.


Sec. 180.203  Definitions.

    In addition to the definitions contained in Secs. 171.8 and 178.69 
of this subchapter, the following definitions apply to this subpart:
    Associate Administrator means Associate Administrator for Hazardous 
Materials Safety.
    Commercially free of corrosive components means a hazardous 
material having a dew point at or below minus 46.7  deg.C (minus 52 
deg.F) at 101kPa (1 atmosphere) and free of material that will 
adversely react with the cylinder (e.g. chemical stress corrosion).
    Condemn means a determination that a cylinder is unserviceable for 
the continued transportation of hazardous materials in commerce and 
that the cylinder may not be restored by repair, rebuilding, 
requalification or any other procedure.
    Defect means an imperfection that requires removal of a cylinder 
from service.
    Elastic expansion means the temporary increase in a cylinder's 
volume, due to application of pressure, which is lost when pressure is 
released.
    Filled means an introduction or presence of a hazardous material in 
a cylinder.
    Non-corrosive service means a hazardous material that is not 
corrosive to the materials of construction of a cylinder (including 
valve, pressure relief device, etc.) when moisture is introduced into 
the cylinder.
    Over-heated means a condition in which any part of a cylinder has 
been subjected to a temperature in excess of 176  deg.C (350  deg.F).
    Over-pressurized means a condition in which a cylinder has been 
subjected to an internal pressure in excess of 30% of its test 
pressure.
    Permanent expansion means the permanent increase in a cylinder's 
volume after the test pressure is released (permanent expansion = total 
expansion minus elastic expansion).
    Proof pressure test means a pressure test by interior 
pressurization without the determination of the cylinder's expansion.
    Rebuild means the replacement of a pressure part (e.g. a wall, head 
or pressure fitting) by welding.
    Rejected cylinder means a cylinder that can not be used for the 
transportation of a hazardous material in commerce without repair, 
rebuild or requalification.
    Repair means a procedure for correction of a rejected cylinder and 
may involve welding.
    Requalification means the completion of a visual inspection and or 
the test(s) that are required to be performed on a cylinder to 
determine its suitability for continued service.
    Requalification identification number or RIN means a code assigned 
by DOT to uniquely identify a cylinder requalification, repair or 
rebuilding facility.
    Test pressure means the pressure used for the requalification of a 
cylinder.
    Total expansion means the total increase in a cylinder's volume due 
to application of the test pressure.
    Visual inspection means an internal or external visual examination, 
or both, performed as part of the cylinder requalification process.
    Volumetric expansion test means a pressure test by interior 
pressurization to measure a cylinder's expansion by using the water 
jacket or direct expansion methods:
    (1) Water jacket method means a volumetric expansion test to 
determine a cylinder's total and permanent expansion by measuring the 
difference between the volume of water the cylinder externally 
displaces at test pressure and the volume of water the cylinder 
externally displaces at ambient pressure.
    (2) Direct expansion method means a volumetric expansion test to 
calculate a cylinder's total and permanent expansion by measuring the 
amount of water forced into a cylinder at test pressure, adjusted for 
the compressibility of water, as a means of determining the expansion.


Sec. 180.205  General requirements for requalification of cylinders.

    (a) General. Each cylinder used for the transportation of hazardous 
materials must be an authorized packaging. To qualify as an authorized 
packaging, each cylinder must conform to this subpart, the applicable 
requirements specified in part 173 of this subchapter, and the 
applicable requirements of subpart C of part 178 of this subchapter.
    (b) Persons performing requalification functions. No person may 
represent that a repair or requalification of a cylinder has been 
performed unless that person holds a current approval issued under the 
procedural requirements prescribed in subpart I of part 107 of this 
chapter. No person may mark a cylinder with a RIN and a requalification 
date or otherwise represent that a DOT specification or exemption 
cylinder has been requalified unless all applicable requirements of 
this subpart have been met. A person who requalifies cylinders shall 
maintain, at each location at which it inspects, tests or marks 
cylinders, the records prescribed in Sec. 180.215.
    (c) Periodic requalification of cylinders. Each cylinder bearing a 
DOT specification marking must be requalified and marked as specified 
in the Requalification Table in this subpart. Each cylinder bearing a 
DOT exemption number must be requalified and marked in conformance with 
this section and the terms of the applicable exemption. No cylinder may 
be charged or filled with a hazardous material and offered for 
transportation in commerce unless that cylinder has been successfully 
requalified and marked in accordance with this subpart. A cylinder may 
be requalified at any time during the month and year that the 
requalification is due. However, a cylinder that was charged or filled 
before the requalification became due may remain in service until it 
has been emptied.
    (1) Each cylinder that successfully passes requalification 
specified in this section must be marked in accordance with 
Sec. 180.213.
    (2) Each cylinder that fails requalification must be:

[[Page 58513]]

    (i) Rejected and may be requalified in accordance with 
Sec. 180.211; or
    (ii) Condemned in accordance with paragraph (i) of this section.
    (3) For nonmetric-marked DOT specification cylinders, the marked 
service pressure may be changed upon application to the Associate 
Administrator and receipt of written procedures.
    (4) For a metric-marked cylinder, the start-to-discharge pressure 
of a pressure relief device must not be less than the marked test 
pressure of the cylinder. For a nonmetric-marked DOT-3 series cylinder, 
the start-to-discharge pressure of a pressure relief device must be set 
to not less than 100% of the minimum required test pressure at the 
first requalification due on and after [EFFECTIVE DATE OF THE FINAL 
RULE]. To ensure that the relief device does not open below its set 
pressure, the allowable tolerances for all the pressure relief devices 
must range from zero to plus 10% of its setting.
    (d) Conditions requiring test and inspection of cylinders. Without 
regard to any other periodic requalification requirements, a cylinder 
must be tested and inspected in accordance with this section prior to 
further use if--
    (1) The cylinder shows evidence of dented, corroded, cracked or 
abraded areas, leakage, thermal damage or any other condition that 
might render it unsafe for use in transportation.
    (2) The cylinder has been in an accident and has been damaged to an 
extent that may adversely affect its lading retention capability.
    (3) The cylinder has been over-heated or over-pressurized.
    (4) The Associate Administrator determines that the cylinder may be 
in an unsafe condition.
    (e) Cylinders containing Class 8 materials. A cylinder that 
previously contained a Class 8 material may not be used to transport a 
Class 2 material in commerce unless the cylinder is--
    (1) Visually inspected, internally and externally, in accordance 
with paragraph (f) of this section and the inspection is recorded as 
prescribed in Sec. 180.215;
    (2) Requalified in accordance with this section, regardless of the 
date of the previous requalification;
    (3) Marked in accordance with Sec. 180.213;
    (4) Decontaminated and the decontamination removes all significant 
residue or impregnation of the Class 8 material.
    (f) Visual inspection. Except as otherwise provided in this 
subpart, each time a cylinder is pressure tested, it must be given an 
internal and external visual inspection. When a pressure test is not 
performed, the cylinder must be given an external visual inspection.
    (1) The visual inspection must be performed in accordance with the 
following CGA Pamphlets: C-6 for steel and nickel cylinders; C-6.1 for 
seamless aluminum cylinders; C-6.2 for fiber reinforced exemption 
cylinders; C-6.3 for low pressure aluminum cylinders; C-8 for DOT 3HT 
cylinders, and C-13 for DOT 8 series cylinders.
    (2) Each cylinder with a vinyl or plastic coating must have the 
coating completely removed prior to performing the visual inspection.
    (3) Each cylinder subject to visual inspection must be approved, 
rejected or condemned according to the criteria in the applicable CGA 
pamphlet.
    (4) In addition to other requirements prescribed in this paragraph, 
DOT 3AL cylinders must be inspected for evidence of sustained load 
cracking in the neck and shoulder area in accordance with the cylinder 
manufacturer's written recommendations which have been approved in 
writing by the Associate Administrator.
    (g) Pressure test. Unless otherwise excepted, the pressure test 
must be conducted in accordance with the procedures in paragraphs 4, 5 
and 6 and Appendices A and B of CGA Pamphlet C-1. Bands and other 
removable attachments must be loosened or removed before testing so 
that the cylinder is free to expand in all directions.
    (h) Cylinder rejection. A cylinder must be rejected when, after a 
visual inspection, it meets a condition for rejection under the visual 
inspection requirements of paragraph (f) of this section.
    (1) A cylinder that is rejected may not be marked as meeting the 
requirements of this section.
    (2) The requalifier shall notify the cylinder owner, in writing, 
that the cylinder has been rejected and, unless requalified as provided 
in Sec. 180.211, may not be filled with a hazardous material for 
transportation in commerce where use of a specification packaging is 
required.
    (3) A rejected nonmetric-marked cylinder with a service pressure of 
less than 900 psig may be requalified and marked if the cylinder is 
repaired or rebuilt and subsequently inspected and tested in 
conformance with--
    (i) The visual inspection requirements of paragraph (f) of this 
section;
    (ii) Part 178 of this subchapter and this part;
    (iii) Any exemption covering the manufacture, requalification, and 
or use of that cylinder; and
    (iv) Any approval required under Sec. 180.211.
    (i) Cylinder condemnation. (1) A cylinder must be condemned when--
    (i) The cylinder meets a condition for condemnation under the 
visual inspection requirements of paragraph (f) of this section;
    (ii) The cylinder leaks through its wall;
    (iii) Evidence of cracking exists to the extent that the cylinder 
is likely to be weakened appreciably;
    (iv) A DOT specification cylinder (including 4M), other than a DOT 
4E aluminum cylinder or an exemption cylinder, permanent expansion 
exceeds 10 percent of total expansion;
    (v) A DOT 3HT cylinder--
    (A) Yields an elastic expansion exceeding the marked rejection 
elastic expansion (REE) value during the pressure test. A cylinder made 
before January 17, 1978, and not marked with an REE in cubic 
centimeters near the marked original elastic expansion must be so 
marked before the next test date. The REE for the cylinder is 1.05 
times its original elastic expansion;
    (B) Shows evidence of denting or bulging; or
    (C) Bears a manufacture or an original test date older than twenty-
four years or after 4,380 pressurizations, whichever occurs first. If a 
cylinder is refilled, on average, more than once every other day, an 
accurate record of the number of rechargings must be maintained by the 
cylinder owner or the owner's agent;
    (vi) A DOT 4E or 4M aluminum cylinder's permanent expansion exceeds 
12 percent of total expansion;
    (vii) A DOT exemption cylinder's permanent expansion exceeds the 
limit in the applicable exemption, or the cylinder meets another 
criterion for condemnation in the applicable exemption;
    (viii) An aluminum or an aluminum-lined composite exemption 
cylinder is exposed to a temperature exceeding 177  deg.C (350  deg.F); 
or
    (ix) A DOT specification cylinder requalified by ultrasonic 
examination that exceeds the minimum rejection criteria set forth in 
Table II of Sec. 180.207 or Sec. 180.209, as applicable.
    (2) When a cylinder is required to be condemned, the requalifier 
shall stamp a series of X's over the DOT specification number and the 
marked pressure or stamp ``CONDEMNED'' on the shoulder, top head, or 
neck using a steel stamp. Alternatively, at the direction of the owner, 
the requalifier may render the cylinder incapable of

[[Page 58514]]

holding pressure. In addition, the requalifier shall notify the 
cylinder owner, in writing, that the cylinder is condemned and may not 
be filled with hazardous material for transportation in commerce where 
use of a specification packaging is required.
    (3) No person may remove or obliterate the ``CONDEMNED'' marking.


Sec. 180.207  Requirements for requalification of metric-marked 
specification cylinders.

    (a) Each metric-marked cylinder that becomes due for periodic 
requalification as specified in Table I of this section must be 
inspected, tested, and marked in conformance with the requirements of 
this subpart. The ultrasonic examination must meet the requirements in 
Table II of this section. The recordkeeping requirements for an 
ultrasonic examination must be in accordance with Sec. 180.215. The 
ultrasonic examination procedures and equipment must be approved by the 
Associate Administrator and meet the requirements set forth in Appendix 
B of Subpart C of Part 178 of this subchapter. Other nondestructive 
examinations (NDE) may be used only if approved in writing by the 
Associate Administrator.
    (b) Except as otherwise provided, DOT 3FM, 3ALM and 3M cylinders 
must have 100% of the cylindrical section tested by straight-beam and 
angle-beam. For a DOT 4M cylinder with a marked test pressure greater 
than 70 bar or tensile strength greater than or equal to 830 Kpa 
(120,000 psi), 100% of the cylindrical section must be tested by 
straight-beam and angle-beam. For a DOT 4M cylinder with a marked test 
pressure of 70 bar or less and tensile strength less than 830 Kpa 
(120,000 psi), 100% of the cylindrical section must be tested by 
straight beam if an ultrasonic examination is performed.
    Tables to Sec. 180.207

                                          Table I to Sec.  180.207.--Requalification of Metric-Marked Cylinders
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                     Type of service
         Interval period (years)                Test of  inspection                           Specifications                   -------------------------
                                                                                                                                   First       subseq.
--------------------------------------------------------------------------------------------------------------------------------------------------------
External visual inspection..............  DOT-3M, 3FM, 3ALM, 4M..........  External visual inspections in accordance with the   ...........  ...........
                                                                            applicable CGA pamphlet must be performed in
                                                                            conjunction with the ultrasonic examination.
INTERNAL and EXTERNAL VISUAL INSPECTION.  DOT-4M.........................  Except as otherwise provided, the internal and       ...........  ...........
                                                                            external visual inspections must be performed in
                                                                            conjunction with the pressure test and in
                                                                            accordance with the applicable CGA pamphlet.
Ultrasonic EXAMINATION..................  DOT 3M, 3FM, 3ALM, 4M..........  All, except cylinders used exclusively for the                 5            5
                                                                            material listed below:.
                                          DOT 3M, 3FM, 3ALM..............  (1) Nonliquefied or liquefied, noncorrosive,
                                                                            nontoxic (the LC50 of the lading is not less than
                                                                            5000 ppm) gases that are commercially free from
                                                                            corrosive components, and in cylinders protected
                                                                            externally by a suitable corrosion-resistant
                                                                            coating. A coating on a stainless steel or
                                                                            aluminum cylinder is optional.
                                                                           (2) Class 3 (flammable) liquids without
                                                                            pressurization that are nontoxic (except 6.1 PG
                                                                            III) and are commercially free from corroding
                                                                            components.
                                                                           (3) Class 8 (corrosive) liquids without                       10           10
                                                                            pressurization that are nontoxic (except 6.1 PG
                                                                            III) and do not meet the criteria of Sec.
                                                                            173.137(c)(2) of this subchapter. See restriction
                                                                            in Sec.  180.205(e).
                                          DOT 3M.........................  Anhydrous ammonia commercially free from corrosive            10           10
                                                                            components, and in cylinders protected externally
                                                                            by a suitable corrosion-resistant coating.
                                          DOT 4M (DOT 4M cylinders with a  (1) Nonliquefied or liquefied, noncorrosive,
                                           test pressure of 70 bar or       nontoxic (the LC50 of the lading is not less than
                                           less may be tested by a          5000 ppm) gases that are commercially free from
                                           volumetric expansion test).      corrosive components, and in cylinders protected
                                                                            externally by a suitable corrosion-resistant
                                                                            coating. A coating on a stainless steel or
                                                                            aluminum cylinder is optional.
                                                                           (2) Class 3 liquids without pressurization that are           15           15
                                                                            nontoxic (except 6.1 PG III) and are commercially
                                                                            free from corrosive components.
                                                                           (3) Class 8 (corrosive) liquids without
                                                                            pressurization that are nontoxic (except 6.1 PG
                                                                            III) and do not meet the criteria of Sec.
                                                                            173.137(c)(2) of this subchapter. See restriction
                                                                            in Sec.  180.205(e).
                                          DOT 3M and 4M (DOT 4M cylinders  Specification cylinders used exclusively as fire              12           12
                                           with a test pressure of 70 bar   extinguishers and meeting the limitations in
                                           or less may be tested by a       special provision 18 in Sec.  172.102(c)(1) of
                                           volumetric expansion test).      this subchapter.
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 58515]]


                           Table II to Sec.  180.207.--Criteria for Periodic Ultrasonic Examination of Metric Marked Cylinders
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                          Rejected area
                                                                                                                                        for reduced wall
                                Coverage area                                     Rejectable crack  Rejectable crack                      thickness (t)
                               of cylinder by   Coverage area   Rejectable crack      length in        size in the     Rejectable pit     reduced wall
      DOT specification         straight beam  of cylinder by  depth in sidewall      sidewall       circumferential    size diameter   t=any value less
                                (longitudinal    angle beam        (% of wall       (multiple of      welded joint      (D)  x  depth   than design min.
                                    wave)       (shear wave)       thickness)      wall thickness)      (depth  x                           wall t\1\
                                                                                                         length)                          D=diameter of
                                                                                                                                          the cylinder
--------------------------------------------------------------------------------------------------------------------------------------------------------
3FM..........................  100% of         100% of         10% of Wall......  4 times Wall....  NA..............  3 mm  x  \1/3\    161 mm\2\ or
                                sidewall.       sidewall.      Thickness........  Thickness.......                     of the Designed  0.002D\2\.
                                                                                                                       Wall Thickness.
3ALM.........................  100% of         100% of         15% of Wall......  5 times Wall....  NA..............  3 mm  x  \1/3\    323 mm\2\ or
                                sidewall.       sidewall.      Thickness........  Thickness.......                     of the Designed  0.004D\2\.
                                                                                                                       Wall Thickness.
3M...........................  100% of         100% of         15% of Wall......  5 times Wall....  NA..............  3 mm  x  \1/3\    323 mm\2\ or
                                sidewall.       sidewall.      Thickness........  Thickness.......                     of the Designed  0.004D\2\.
                                                                                                                       Wall Thickness.
4M with a marked test          100% of         100% of         10% of Wall......  4 times Wall....  10% of Wall       3 mm  x  \1/3\    323 mm\2\ or
 pressure >70 bar or tensile    sidewall.       sidewall.      Thickness........  Thickness.......   Thick (Depth)     of the Designed  0.004D\2\.
 strength 830 MPa.                                                                        and 2 times of    Wall Thickness.
                                                                                                     Wall Thick,
                                                                                                     (Length).
4M with a marked test          100% of         NA............  NA...............  NA..............  NA..............  NA..............  323 mm\2\ or
 pressure 70 bar     sidewall.                                                                                               0.004D\2\.
 or tensile strength <830 MPa.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Term wall thickness in this table means the minimum design wall thickness provided in the manufacturers inspection report.

Sec. 180.209  Requirements for requalification of nonmetric-marked 
specification cylinders.

    (a) Periodic qualification of cylinders. (1) Each nonmetric-marked 
cylinder that becomes due for periodic requalification, as specified in 
the following table, must be requalified and marked in conformance with 
the requirements of this subpart. The recordkeeping requirements must 
be in accordance with Sec. 180.215. Table I follows:

       Table I.--Requalification of Nonmetric-marked Cylinders \1\
------------------------------------------------------------------------
  Specification under which       Minimum test
    cylinder was made \2\       pressure (p.s.i.)    Test period (years)
---------------------------------------\3\------------------------------
DOT-3.......................  3,000 p.s.i.........  5.
DOT-3A, 3AA.................  5/3 times service     5, 10, or 12 (see
                               pressure, except      Sec.  180.209 (b),
                               noncorrosive          (f), (h) and (j)).
                               service (see Sec.
                               180.209(g)).
DOT-3AL.....................  5/3 times service      5 or 12 (see
                               pressure.             180.209(j)).
DOT-3AX, 3AAX...............  5/3 times service     5.
                               pressure.
3B, 3BN.....................  2 times service       5 or 10 (see Sec.
                               pressure (see Sec.    180.209(f)).
                               180.209(g)).
3E..........................  Test not required.
3HT.........................  5/3 times service     3 (see Sec.
                               pressure.             180.209(i) and
                                                     180.213(c)).
3T..........................  5/3 times service     5.
                               pressure.
4AA480......................  2 times service       5 or 10 (see Sec.
                               pressure (see Sec.    180.209(e)(14)).
                               180.209(g)).
4B, 4BA, 4BW, 4B-240ET......  2 times service       5, 10 or 12 (see
                               pressure, except      Sec.  180.209(e),
                               non-corrosive         (f) and (j)).
                               service (see Sec.
                               180.209(g)).
4D, 4DA, 4DS................  2 times service        5.
                               pressure.
DOT-4E......................  2 times service        5.
                               pressure, except
                               non-corrosive
                               service (see Sec.
                               180.209(g)).
4L..........................   Test not required
8, 8AL......................  ....................  10 or 20 (See Sec.
                                                     180.209(i)).
Exemption Cylinder Foreign    See current           See current
 cylinder (see Sec.            exemption as marked   exemption 5 (see
 173.301(j) for restrictions   on the cylinder,      Sec.  180.209(k)
 on use.                       but not less than 5/  and Sec.
                               3 of any service or   180.213(d)(iii)).
                               working pressure
                               marking.
------------------------------------------------------------------------
\1\ Any cylinder not exceeding two inches outside diameter and less than
  two feet in length is excepted from hydrostatic test.
\2\ After January 1, 2005, DOT-3T and 3HT specification cylinders must
  be inspected by a non-destructive testing method approved by the
  Associate Administrator.
\3\ For cylinders not marked with a service pressure, see Sec.
  173.301(e)(1) of this subchapter.


[[Page 58516]]

    (2) In lieu of a hydrostatic pressure test (i.e. volumetric 
expansion or proof pressure tests) as required by this section, each 
DOT specification cylinder that becomes due for periodic 
requalification, as specified in Table I of paragraph (a)(1) of this 
section, may be requalified by using one of the following methods:
    (i) Ultrasonic examination: Ultrasonic examination must be in 
conformance with the requirements of the Appendix B of Subpart C of 
part 178 of this subchapter and Table II of paragraph (a)(2) of this 
section. Minimum wall thickness of each cylinder examined by UT must be 
equal to or greater than the design minimum wall thickness. For each 
cylinder, the minimum wall thickness data from the cylinder 
manufacturer's inspection report must be available and used during UT 
examination. An external visual inspection in accordance with the 
applicable CGA pamphlet is required to be performed in conjuction with 
the ultrasonic examination. The recordkeeping requirements for an 
ultrasonic examination must be in accordance with Sec. 180.215. The 
marking requirements for an ultrasonic examination must be in 
accordance with Sec. 180.213.

    Note to paragraph (a)(2)(i): The test interval for the 
requalification of a nonmetric-marked DOT specification cylinder 
subjected to UT examination is the same as specified in Table I of 
paragraph (a)(1) of this section. The ultrasonic examination only 
replaces the hydrostatic pressure test.

    (ii) Other nondestructive examinations (NDE) as approved in writing 
by the Associate Administrator. Table II follows:

                                 Table II.--Criteria for Periodic Ultrasonic Examination of Non-metric Marked Cylinders
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                       Rejected area for
                                                                                                                                         reduced wall
                                                                                                                                         thickness (t)
                                   Coverage area of    Coverage area of    Rejectable defect   Rejectable defect    Rejectable pit     reduced wall t =
            DOT spec                 cylinder by       cylinder by angle   depth in sidewall  length in sidewall   size diameter (D)    any value less
                                    straight beam      beam (shear wave)      (% of wall       (multiple of wall       x  depth        than design min.
                                 (longitudinal wave)                          thickness)          thickness)                             wall t\1\ D =
                                                                                                                                        diameter of the
                                                                                                                                           cylinder
--------------------------------------------------------------------------------------------------------------------------------------------------------
3T.............................  100% of sidewall...  100% of sidewall..  10% of Wall.......  4 times Wall......  3 mm  x  \1/3\ of   161 mm\2\ or
                                                                          Thickness.........  Thickness.........   the Designed Wall  0.002D\2\.
                                                                                                                   Thickness.
3AL (mfg. after 1989)..........  100% of sidewall...  100% of sidewall..  15% of Wall.......  5 times Wall......  3 mm  x  \1/3\ of   323 mm\2\ or
                                                                          Thickness.........  Thickness.........   the Designed Wall  0.004D\2\.
                                                                                                                   Thickness.
3AA,3A, 3AX, 3AAX..............  100% of sidewall...  100% of sidewall..  15% of Wall.......  5 times Wall......  3 mm  x  \1/3\ of   323 mm\2\ or
                                                                          Thickness.........  Thickness.........   the Designed Wall  0.004D\2\.
                                                                                                                   Thickness.
4B,4BA,4BW4D,4DS,4DA...........  100% of sidewall...  NA................  NA................  NA................  3 mm  x  \1/3\ of   323 mm\2\ or
                                                                                                                   the Designed Wall  0.004D\2\.
                                                                                                                   Thickness.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Term wall thickness in this table means the minimum design wall thickness provided in the manufacturers inspection report.

    (b) DOT-3A or 3AA cylinders. (1) A cylinder conforming to 
specification DOT-3A or 3AA with a water capacity of 125 pounds or less 
that is removed from any cluster, bank, group, rack, or vehicle each 
time it is filled, may be requalified every ten years instead of every 
five years, provided the cylinder meets all of the following--
    (i) The cylinder was manufactured after December 31, 1945;
    (ii) The cylinder is used exclusively for air, argon, cyclopropane, 
ethylene, helium, hydrogen, krypton, neon, nitrogen, nitrous oxide, 
oxygen, sulfur hexafluoride, xenon, permitted mixtures of these gases 
(see Sec. 173.301(d) of this subchapter), and permitted mixtures of 
these gases with up to 30 percent by volume of carbon dioxide, provided 
that the gas has a dew point at or below minus (52 deg.F) at 1 
atmosphere;
    (iii) Before each refill, the cylinder is removed from any cluster, 
bank, group, rack or vehicle and passes the hammer test specified in 
CGA Pamphlet C-6;
    (iv) The cylinder is dried immediately after hydrostatic testing to 
remove all traces of water;
    (v) The cylinder is not used for underwater breathing; and
    (vi) Each cylinder is stamped with a five-pointed star at least 
one-fourth of an inch high immediately following the test date.
    (2) If, since the last required requalification, a cylinder has not 
been used exclusively for the gases specifically identified in 
paragraph (b)(1)(ii) of this section, but currently conforms with all 
other provisions of paragraph (b)(1) of this section, it may be 
requalified every 10 years instead of every five years, provided it is 
first requalified and examined as prescribed by Sec. 173.302a(b)(2), 
(3) and (4) of this subchapter.
    (3) Except as specified in (b)(2) of this section, if a cylinder, 
marked with a star, is filled with a compressed gas other than as 
specified in paragraph (b)(1)(ii) of this section, the star following 
the most recent test date must be obliterated. The cylinder must be 
requalified five years from the marked test date, or prior to the first 
filling with a compressed gas, if the required five-year 
requalification period has passed.

[[Page 58517]]

    (c) DOT 4-series cylinders. A DOT 4-series cylinder, except 4L 
cylinders, that at any time shows evidence of a leak or of internal or 
external corrosion, denting, bulging or rough usage to the extent that 
it is likely to be weakened appreciably; or that has lost five percent 
or more of its official tare weight must be requalified before being 
refilled and offered for transportation. (Refer to CGA Pamphlet C-6 or 
C-6.3, as applicable, regarding cylinder weakening.) After testing, the 
actual tare weight must be recorded as the new tare weight.
    (d) Cylinders 12 pounds or less with service pressures of 300 psi 
or less. A cylinder of 12 pounds or less water capacity authorized for 
service pressure of 300 psi or less must be given a complete external 
visual inspection at the time periodic requalification becomes due. 
External visual inspection must be in accordance with CGA Pamphlet C-6 
or C-6.1. The cylinder may be hydrostatically tested without a water 
jacket and without determining total and permanent expansions. The test 
is successful if the cylinder, when examined under test pressure, does 
not display a defect described in Sec. 180.205(i)(1)(ii) or (iii).
    (e) Proof pressure test. A cylinder made in compliance with 
specification DOT 4B, DOT 4BA, DOT 4BW, DOT 4E that is used exclusively 
for anhydrous dimethylamine; anhydrous methylamine; anhydrous 
trimethylamine; methyl chloride; liquefied petroleum gas; 
methylacetylene-propadiene stabilized; or dichlorodifluoromethane, 
difluoroethane, difluorochloroethane, chlorodifluoromethane, 
chlorotetrafluoroethane, trifluorochloroethylene, or mixture thereof, 
or mixtures of one or more with trichlorofluoromethane; and that is 
commercially free from corroding components and protected externally by 
a suitable corrosion-resistant coating (such as galvanizing or 
painting) may be requalified every 12 years instead of every five 
years. Alternatively, the cylinder may be subjected to internal 
hydrostatic pressure of at least two times the marked service pressure 
without determination of expansion, but this latter type of test must 
be repeated every seven years after expiration of the first 12-year 
period. When subjected to the latter test, the cylinder must be 
carefully examined under test pressure and removed from service if a 
leak or other harmful defect exists. A cylinder requalified by the 
proof pressure test method must be marked after a test or an inspection 
with the appropriate RIN and the date of requalification or 
reinspection on the cylinder followed by an ``S''.
    (f) Poisonous materials. A cylinder conforming to specification 
DOT-3A, DOT-3AA, DOT-3B, DOT-4BA or DOT-4BW having a service pressure 
of 300 psi or less that is used exclusively for methyl bromide, liquid; 
mixtures of methyl bromide and ethylene dibromide, liquid; mixtures of 
methyl bromide and chlorpicrin, liquid; mixtures of methyl bromide and 
petroleum solvents, liquid; or methyl bromide and nonflammable, 
nonliquefied compressed gas mixtures, liquid; that is commercially free 
of corroding components, and that is protected externally by a suitable 
corrosion resistant coating (such as galvanizing or painting) and 
internally by a suitable corrosion resistant lining (such as 
galvanizing) may be tested every 10 years instead of every five years, 
provided that a visual internal and external examination of the 
cylinder is conducted every five years in accordance with CGA Pamphlet 
C-6. The cylinder must be examined at each filling, and rejected if a 
dent, corroded area, leak or other condition indicates possible 
weakness.
    (g) Visual inspections. A cylinder conforming to a specification 
listed in the table in this paragraph and used exclusively in the 
service indicated may, instead of a periodic hydrostatic test, be given 
a complete external visual inspection at the time periodic 
requalification becomes due. External visual inspection must be in 
accordance with CGA Pamphlet C-6 or C-6.3, as applicable. When this 
inspection is used instead of hydrostatic pressure testing, subsequent 
inspections are required at five-year intervals after the first 
inspection. Inspections must be made only by persons holding a current 
RIN and the results recorded and maintained in accordance with 
Sec. 180.215. Records shall include: date of inspection (month and 
year); DOT specification number; cylinder identification (registered 
symbol and serial number, date of manufacture, and owner); type of 
cylinder protective coating (including statement as to need of 
refinishing or recoating); conditions checked (e.g., leakage, 
corrosion, gouges, dents or digs in shell or heads, broken or damaged 
footring or protective ring or fire damage); disposition of cylinder 
(returned to service, returned to cylinder manufacturer for repairs or 
condemned). A cylinder passing requalification by the external visual 
inspection must be marked in accordance with Sec. 180.213. 
Specification cylinders must be in exclusive service as follows:

------------------------------------------------------------------------
  Cylinders made in compliance with--         Used exclusively for--
------------------------------------------------------------------------
DOT-3A, DOT-3AA, DOT-3A480X, DOT-4AA480  Anhydrous ammonia of at least
                                          99.95% purity.
DOT-3A, DOT-3AA, DOT-3A480X, DOT-3B,     Butadiene, inhibited, which is
 DOT-4B, DOT-4BA, DOT-4BW.                commercially free from
                                          corroding components.
DOT-3A, DOT-3A480X, DOT-3AA, DOT-3B,     Cyclopropane which is
 DOT-4AA480, DOT-4B, DOT-4BA, DOT-4BW.    commercially free from
                                          corroding components.
DOT-3A, DOT-3AA, DOT-3A480X, DOT-4B,     Fluorinated hydrocarbons and
 DOT-4BA, DOT-4BW, DOT-4E.                mixtures thereof which are
                                          commercially free from
                                          corroding components.
DOT-3A, DOT-3AA, DOT-3A480X, DOT-3B,     Liquefied hydrocarbon gas which
 DOT-4B, DOT-4BA, DOT-4BW, DOT-4E.        is commercially free from
                                          corroding components.
DOT-3A, DOT-3AA, DOT-3A480X, DOT-3B,     Liquefied petroleum gas which
 DOT-4B, DOT-4BA, DOT-4BW, DOT-4E.        is commercially free from
                                          corroding components.
DOT-3A, DOT-3AA, DOT-3B, DOT-4B, DOT-    Methylacetylene-propadiene,
 4BA, DOT-4BW, DOT-4E.                    stabilized, which is
                                          commercially free from
                                          corroding components.
DOT-3A, DOT-3AA, DOT-3B, DOT-4B, DOT-    Anhydrous mono, di,
 4BA, DOT-4BW.                            trimethylamines which are
                                          commercially free from
                                          corroding components.
DOT-4B240, DOT-4BW240..................  Ethyleneimine, inhibited.
------------------------------------------------------------------------

    (h) Cylinders containing anhydrous ammonia. A cylinder made in 
compliance with specification DOT-3A, DOT-3A480X, or DOT-4AA480 used 
exclusively for anhydrous ammonia, commercially free from corroding 
components, and protected externally by a suitable corrosion-resistant 
coating (such as painting) may be requalified every 10 years instead of 
every five years.

[[Page 58518]]

    (i) Requalification of DOT 8 series cylinders. (1) Each owner of a 
DOT 8 series cylinder used to transport acetylene must have the 
cylinder shell and the porous filler requalified in accordance with CGA 
Pamphlet C-13. Requalification must be performed in accordance with the 
following schedule:

----------------------------------------------------------------------------------------------------------------
                                       Shell (visual inspection)             Porous filler requalification
                                            requalification           ------------------------------------------
  Date of cylinder manufacture  --------------------------------------
                                      Initial           Subsequent          Initial             Subsequent
----------------------------------------------------------------------------------------------------------------
Before January 1, 1991.........  Before January 1,  10 years.........  Before January 1,  Not required.
                                  2001.                                 2011.
On or after January 1, 1991....  10 years \1\.....  10 years.........  3 to 20 years \2\  Not required.
----------------------------------------------------------------------------------------------------------------
\1\ Years from date of cylinder manufacture.
\2\ For a cylinder manufactured on or after January 1, 1991, requalification of the porous filler must be
  performed no sooner than 3 years, and no later than 20 years, from the date of manufacture.

    (2) Unless requalified and marked in accordance with CGA Pamphlet 
C-13 before October 1, 1994, an acetylene cylinder must be requalified 
by a person who holds a current RIN.
    (3) If a cylinder valve is replaced, a cylinder valve of the same 
weight must be used or the tare weight of the cylinder must be adjusted 
to compensate for valve weight differential.
    (4) The person performing a visual inspection, or requalification 
must record the results as specified in Sec. 180.215.
    (5) The person performing a visual inspection, or requalification 
must mark the cylinder as specified in Sec. 180.213.
    (j) Cylinders used as a fire extinguisher. Only DOT specification 
cylinders used as fire extinguishers and meeting Special Provision 18 
in Sec. 172.102(c)(1) of this subchapter may be requalified in 
accordance with this paragraph (j).
    (1) A DOT specification 4B, 4BA, 4B240ET or 4BW cylinder may be 
tested as follows:
    (i) For a cylinder with a water capacity of 12 pounds or less by 
volumetric expansion test using the water jacket method or by proof 
pressure test. A requalification must be performed 12 years after the 
original test date and at 12-year intervals thereafter.
    (ii) For a cylinder having a water capacity over 12 pounds--
    (A) By proof pressure test. A requalification must be performed 12 
years after the original test date and at 7-year intervals; or
    (B) By volumetric expansion test using the water jacket method. A 
requalification must be performed 12 years after the original test date 
and at 12-year intervals thereafter.
    (2) A DOT specification 3A, 3AA, or 3AL cylinder must be 
requalified by volumetric expansion test using the water jacket method. 
A requalification must be performed 12 years after the original test 
date and at 12-year intervals thereafter.
    (k) Requalification of foreign cylinders filled for export.
    (1) A cylinder manufactured outside the United States, other than 
as provided in Sec. 171.12a of this subchapter, that has not been 
manufactured, inspected, tested and marked in accordance with part 178 
of this subchapter may be filled with compressed gas in the United 
States, and shipped solely for export if it meets the following 
requirements, in addition to other requirements of this subchapter:
    (i) It has been inspected, tested and marked (with only the month 
and year of test) in conformance with the procedures and requirements 
of this subpart or the Associate Administrator has authorized the 
filling company to fill foreign cylinder under an alternative method of 
qualification; and
    (ii) It is offered for transportation in conformance with the 
requirements of Sec. 173.301(l) of this subchapter.
    (2) [Reserved]


Sec. 180.211  Repair, rebuilding and reheat treatment of nonmetric-
marked DOT-4 series specification cylinders.

    (a) General requirements for repair and rebuilding. Any repair or 
rebuilding of a DOT 4B, 4BA or 4BW cylinder must be performed by a 
person holding an approval as specified in Sec. 107.805 of this 
chapter. A person performing a rebuild function shall be considered a 
manufacturer subject to the requirements of Sec. 178.2(a)(2) and 
subpart C of part 178 of this subchapter. The person performing a 
repair, rebuild, or reheat treatment must record the test results as 
specified in Sec. 180.215. Each cylinder that is successfully repaired 
or rebuilt must be marked in accordance with Sec. 180.213.
    (b) General repair requirements. Any repair of a cylinder must be 
made in accordance with the following:
    (1) The repair and the inspection of the work performed must be 
made in accordance with the requirements of the cylinder specification.
    (2) The person performing the repair shall use the procedure, 
equipment, and filler metal or brazing material as authorized by the 
approval issued under Sec. 107.805 of this chapter.
    (3) Welding and brazing shall be performed on an area free from 
contaminants.
    (4) A weld defect, such as porosity in a pressure retaining seam, 
shall be completely removed before rewelding. Puddling may be used to 
remove a weld defect only by the tungsten inert gas shielded arc 
process.
    (5) After removal of a non-pressure attachment and before its 
replacement, the cylinder shall be given a visual inspection in 
accordance with Sec. 180.205(f).
    (6) Reheat treatment of DOT-4B, 4BA or 4BW specification cylinders 
after replacement of non-pressure attachments is not required when the 
total weld material does not exceed 8 inches. Individual welds must be 
at least three inches apart.
    (7) After repair of a DOT 4B, 4BA or 4BW cylinder, the weld area is 
to be leak tested at the service pressure of the cylinder.
    (8) Repair of weld defects must be free of cracks.
    (9) When a non-pressure attachment with the original cylinder 
specification markings is replaced, all markings must be transferred to 
the attachment on the repaired cylinder.
    (10) Walls, heads or bottoms of cylinders with defects or leaks in 
base metal may not be repaired, but may be replaced as provided for in 
paragraph (d) of this section.
    (c) Additional repair requirements for 4L cylinders. (1) Repairs to 
a DOT 4L cylinder are limited to the following:
    (i) The removal of either end of the insulation jacket to permit 
access to the cylinder, piping system, or neck tube.
    (ii) The replacement of the neck tube. At least a 13 mm (0.51 inch) 
piece of the original neck tube must be protruding above the cylinder's 
top end. The original weld attaching the neck tube to the cylinder must 
be sound and the replacement neck tube must be welded to this remaining 
piece of the original neck tube.
    (iii) The replacement of material such as, but not limited to, the 
insulating material and the piping system within

[[Page 58519]]

the insulation space is authorized. The replacement material must be 
equivalent to that used at the time of original manufacture.
    (iv) Other welding procedures which are qualified by CGA Pamphlet 
C-3, and not excluded by the definition of rebuild, are authorized.
    (2) After repair, the cylinder must be:
    (i) Pressure tested in accordance with the specifications under 
which the cylinder was originally manufactured;
    (ii) Leak tested before and after assembly of the insulation jacket 
using a mass spectrometer detection system; and
    (iii) Tested for heat conductivity requirements.
    (d) General rebuilding requirements. (1) The rebuilding of a 
cylinder must be made in accordance with the following requirements:
    (i) The person rebuilding the cylinder must use the procedures and 
equipment as authorized by the approval issued under Sec. 107.805 of 
this chapter.
    (ii) After removal of a non-pressure component and before 
replacement of any non-pressure component, the cylinder must be 
visually inspected in accordance with CGA Pamphlet C-6.
    (iii) The rebuilder may rebuild a DOT 4B, 4BA or 4BW cylinder 
having a water capacity of 20 pounds or greater by replacing a head of 
the cylinder using a circumferential joint. When this weld joint is 
located at other than an original welded joint, a notation of this 
modification shall be shown on the Manufacturer's Report of Rebuilding 
in Sec. 180.215(d)(2). Weld joint must be on the cylindrical section of 
the cylinder.
    (iv) Any welding and the inspection of the rebuilt cylinder must be 
in accordance with the requirements of the applicable cylinder 
specification and the following requirements:
    (A) Rebuilding of any cylinder involving a joint subject to 
internal pressure may only be performed by fusion welding;
    (B) Welding shall be performed on an area free from contaminants; 
and
    (C) A weld defect, such as porosity in a pressure retaining seam, 
shall be completely removed before rewelding. Puddling may be used to 
remove a weld defect only by the tungsten inert gas shielded arc 
process.
    (2) Any rebuilt cylinder must be--
    (i) Heat treated in accordance with paragraph (f) of this section;
    (ii) Subjected to a volumetric expansion test on each cylinder as 
specified in CGA Pamphlet C-1, paragraphs 4 or 5, and Appendices A and 
B. The results of the tests must conform with the applicable cylinder 
specification;
    (iii) Inspected and have test data reviewed to determine 
conformance with the applicable cylinder specification; and
    (iv) Made of material that conforms to the specification. 
Determination of conformance shall include chemical analysis, 
verification, inspection and tensile testing of the replaced part. 
Tensile tests must be performed on the replaced part after heat 
treatment by lots defined in the applicable specification.
    (3) A record of rebuilding must be completed for each cylinder 
rebuilt in the format presented in Sec. 180.215(d).
    (4) Rebuilding a cylinder with brazed seams is prohibited.
    (5) When an end with the original cylinder specification markings 
is replaced, all markings must be transferred to the rebuilt cylinder.
    (e) Additional rebuilding requirements for DOT-4L cylinders. (1) 
The rebuilding of a DOT 4L cylinder is:
    (i) Substituting or adding material in the insulation space not 
identical to that used in the original manufacture of that cylinder;
    (ii) Making a weld repair not to exceed 150 mm (5.9 inches) in 
length on the longitudinal seam of the cylinder or 300 mm (11.8 inches) 
in length on a circumferential weld joint of the cylinder; or
    (iii) Replacing the outer jacket.
    (2) Reheat treatment of cylinders is prohibited.
    (3) After rebuilding, each inner containment vessel must be proof 
pressure tested at 2 times its service pressure. Each completed 
assembly must be leak-tested using a mass spectrometer detection 
system.
    (f) Reheat treatment. (1) Prior to reheat treatment, each cylinder 
must be given a visual inspection, internally and externally, in 
accordance with Sec. 180.205(f).
    (2) Cylinders must be segregated in lots for reheat treatment. The 
reheat treatment and visual inspection must be performed in accordance 
with the specification for the cylinders except as provided in 
paragraph (f)(4) of this section.
    (3) After reheat treatment, each cylinder in the lot must be 
subjected to a volumetric expansion test and meet the acceptance 
criteria in the applicable specification or be scrapped.
    (4) After all welding and heat treatment, a test of the new weld 
must be performed as required by the original specification. The test 
results must be recorded in accordance with Sec. 180.215.


Sec. 180.213  Requalification markings.

    (a) General. Each cylinder that has been requalified in accordance 
with this subpart with acceptable results must be marked as specified 
in this section. Required markings may not be altered or removed.
    (b) Placement of markings. Each cylinder must be plainly and 
permanently marked into the metal of the cylinder as permitted by the 
applicable specification. Unless authorized by the cylinder 
specification, marking on the cylinder sidewall is prohibited.
    (1) Required specification markings must be legible so as to be 
readily visible at all times. Markings that are becoming illegible may 
be remarked on the cylinder as provided by the original specification. 
The markings may be placed on any portion of the upper end of the 
cylinder excluding the sidewall. No steel stamping, engraving, or 
scribing may be made in the sidewall of the cylinder unless 
specifically permitted in the applicable cylinder specification. A 
metal plate if used, must be attached as provided by the original 
specification.
    (2) Markings of previous tests may not be obliterated, except when 
the space originally provided for requalification dates becomes filled, 
additional dates may be added as follows:
    (i) All preceding test dates may be removed by peening provided 
that--
    (A) Permission is obtained from the cylinder owner;
    (B) The minimum wall thickness is maintained in accordance with 
manufacturing specifications for the cylinder; and
    (C) The original manufacturing test date is not removed.
    (ii) When the cylinder is fitted with a footring, additional dates 
may be marked on the external surface of the footring.
    (c) Marking method. The depth of markings may be no greater than 
that specified in the applicable specification. The markings must be 
made by stamping, engraving, scribing or any method approved in writing 
by the Associate Administrator.
    (1) A cylinder used as a fire extinguisher (Sec. 180.209(j)) may be 
marked by using a pressure sensitive label.
    (2) For a DOT 3HT cylinder, the test date and RIN must be applied 
by low-stress steel stamps to a depth no greater than that prescribed 
at the time of manufacture. Stamping on the sidewall is not authorized.
    (d) Requalification markings. (1) Each cylinder that has 
successfully passed requalification must be marked with the RIN set in 
a square pattern, between the month and year of the requalification 
date. The first character of the RIN must

[[Page 58520]]

appear in the upper left corner of the square pattern; the second in 
the upper right; the third in the lower right, and the fourth in the 
lower left. Example: A cylinder requalified in September 1998, and 
approved by a person who has been issued RIN ``A123'', would be marked 
plainly and permanently into the metal of the cylinder in accordance 
with location requirements of the cylinder specification or on a metal 
plate permanently secured to the cylinder in accordance with paragraph 
(b) of this section:

[GRAPHIC] [TIFF OMITTED] TP30OC98.007


    (2) Upon a written request, variation from the marking requirement 
may be approved by the Associate Administrator.
    (3) Exception. A cylinder subject to the requirements of 
Sec. 173.301(l) of this subchapter may not be marked with a RIN.
    (e) Size of markings. The size of the markings must be at least 
6.35 mm (\1/4\ in.) high, except that RIN characters must be at least 
3.18 mm (\1/8\ in.) high.
    (f) Illustrations of the required marking information for metric-
marked cylinders and exemption cylinders after requalification are as 
follows:

    (1) Ultrasonic examination:
    [GRAPHIC] [TIFF OMITTED] TP30OC98.008
    

    (2) Volumetric expansion test:
    [GRAPHIC] [TIFF OMITTED] TP30OC98.009
    

    (g) Illustrations of the required marking information for 
nonmetric-marked cylinders and exemption cylinders after 
requalification are as follows:
    (1) 5-year volumetric expansion test; 10-year volumetric expansion 
test (cylinders conforming to Sec. 180.209(f) and (h)); or 12-year 
volumetric expansion test(fire extinguishers conforming to 
Sec. 173.309(b) of this subchapter and cylinders conforming to 
Sec. 180.209(e)and Sec. 180.209(g)):

[GRAPHIC] [TIFF OMITTED] TP30OC98.010


    (2) 10-year volumetric expansion test(cylinders conforming to 
Sec. 180.209(b)):
[GRAPHIC] [TIFF OMITTED] TP30OC98.011


    (3) Special filling limits up to 10% in excess of the marked 
service pressure (cylinders conforming to Sec. 173.302a(b) of this 
subchapter):

[GRAPHIC] [TIFF OMITTED] TP30OC98.012


    (4) Proof pressure test (fire extinguishers conforming to 
Sec. 173.309(b) of this subchapter and cylinders conforming to 
Sec. 180.209(e)):

[GRAPHIC] [TIFF OMITTED] TP30OC98.013


    (5) 5-year external visual inspection (cylinders conforming to 
Sec. 180.209(g)):

[GRAPHIC] [TIFF OMITTED] TP30OC98.014


    (6) Requalification after a repair procedure and volumetrically 
tested (cylinders conforming to Sec. 180.211):

[GRAPHIC] [TIFF OMITTED] TP30OC98.015


    (7) Requalification after a repair procedure and proof pressure 
tested (cylinders conforming to Sec. 180.211):

[GRAPHIC] [TIFF OMITTED] TP30OC98.016


    (8) Requalification after a rebuilding procedure:

    [GRAPHIC] [TIFF OMITTED] TP30OC98.017
    

    (9) DOT 8 series cylinder shell reinspection only:

    [GRAPHIC] [TIFF OMITTED] TP30OC98.018
    

    (10) DOT 8 series cylinder shell and porous filler reinspection:

    [GRAPHIC] [TIFF OMITTED] TP30OC98.019
    

Sec. 180.215  Reporting and record retention requirements.

    (a) Facility records. A person who requalifies, repairs or rebuilds 
cylinders shall maintain the following records where the 
requalification is performed:
    (1) Current RIN issuance letter;
    (2) If the RIN has expired and renewal is pending, a copy of the 
renewal request;
    (3) Copies of notifications to Associate Administrator required 
under Sec. 107.805 of this subchapter;
    (4) Current copies of those portions of this subchapter that apply 
to its cylinder requalification and marking activities at that 
location;
    (5) Current copies of all exemptions governing exemption cylinders 
requalified or marked by the requalifier at that location; and
    (6) The information contained in each applicable CGA or ASTM 
standard incorporated by reference in Sec. 171.7 of this subchapter 
that applies to the requalifier's activities. This information must be 
the same as contained in the edition incorporated by reference in 
Sec. 171.7 of this subchapter.
    (b) Requalification records. Daily records of visual inspection, 
pressure test, and ultrasonic examination, as applicable, must be 
maintained by the person who performs the requalification until either 
the expiration of the requalification period or until the cylinder is 
again requalified, whichever occurs first. A single date may be used 
for each test sheet, provided each test on the sheet was conducted on 
that date. Ditto marks or a solid vertical line may be used to indicate 
repetition of the preceding entry for the following entries: date; 
actual dimensions; if present, manufacturer's name or symbol; if 
present, owner's name or symbol and test operator. Blank spaces may not 
be used to indicate repetition of a prior entry. The records must 
include the following information:
    (1) Pressure test records. For each test to demonstrate 
calibration, the date; serial number of the calibrated cylinder; 
calibration test pressure; total, elastic and permanent expansions; and 
legible identification of test operator. The test operator must be able 
to demonstrate that the results of the daily calibration verification 
correspond to the hydrostatic tests that were performed on that day. 
The daily verification of calibration(s) may be recorded on the same 
sheets as, and with, test records for that date.
    (2) Pressure test and visual inspection records. The date of 
requalification; serial number; DOT specification or exemption number; 
marked pressure; actual dimensions; if present,

[[Page 58521]]

manufacturer's name or symbol; if present, owner's name or symbol; 
result of visual inspection; actual test pressure; total, elastic and 
permanent expansions; percent permanent expansion; disposition, with 
reason for any repeated test, rejection or condemnation; and legible 
identification of test operator. For each cylinder marked pursuant to 
Sec. 173.302a(b)(5) of this subchapter, the test sheet must indicate 
the method by which any average or maximum wall stress was computed. 
Records must be kept for all completed, as well as unsuccessful tests. 
The entry for a second test under CGA Pamphlet C-1 after a failure to 
hold test pressure, must indicate the date of the earlier inspection or 
test.
    (3) Wall stress. Calculations of average and maximum wall stress 
pursuant to Sec. 173.302a(b)(3) of this subchapter, if performed;
    (4) Calibration certificates. The most recent certificate of 
calibration must be maintained for each calibrated cylinder.
    (5) Ultrasonic examination records. The information prescribed in 
ASTM E 797 or ASTM E 213 as applicable.
    (c) Repair, rebuilding or reheat treatment records. (1) Records 
covering welding or brazing repairs, rebuilding or reheat treating 
shall be retained for a minimum of fifteen years by the approved 
facility.
    (2) A record for rebuilding, in accordance with Sec. 180.211(d), 
must be completed for each cylinder rebuilt. The record must be clear, 
legible, and contain the following information:

Cylinder Identification

Original Manufacturer--------------------------------------------------
Cylinder Specification Number and Service
Pressure---------------------------------------------------------------

Cylinder Serial Number-------------------------------------------------

Date at Original Manufacturer------------------------------------------

Other Identification Marks---------------------------------------------

Chemical Analysis of Replacement Parts

Parts Being Replaced---------------------------------------------------

Heat Identification----------------------------------------------------

Steel Manufactured by--------------------------------------------------

Analysis Performed by--------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------------------------------
      C             P             S            Si            Mn            Ni            Cr            Mo            Cu            Al            Zn
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------

Record of Physical Test of Replacement Parts

----------------------------------------------------------------------------------------------------------------
                                        Elongation in    Reduction in area
    Yield PSI         Tensile PSI           inches               %              Weld bend         Weld tensile
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------

Record of Volumetric Expansion Test

    Calculated volumetric capacity of the cylinder being rebuilt-
________________ lbs.

------------------------------------------------------------------------
                                               Percent of
 Actual test       Total        Permanent       total to     Volumetric
   pressure      expansion      expansion      permanent      capacity
------------------------------------------------------------------------
------------------------------------------------------------------------

(Permanent expansion may not exceed 10% of the total expansion) 
(Volumetric capacity of a rebuilt cylinder must be within plus or 
minus 3% at the calculated capacity)
    I certify that this rebuilt cylinder is accurately represented 
by the data above and complies with all of the requirements in 
Subchapter C of 49 CFR.

Repair Technician------------------------------------------------------

Date-------------------------------------------------------------------

Company Representative-------------------------------------------------

Date-------------------------------------------------------------------
    Issued in Washington D.C. on October 15, 1998, under authority 
delegated in 49 CFR Part 106, Appendix A.
Alan I. Roberts,
Associate Administrator for Hazardous Materials Safety.
[FR Doc. 98-28118 Filed 10-26-98; 10:46 am]
BILLING CODE 4910-60-P