http://go.asme.org/PHMSA-ASME-PRM.
    The Compressed Gas Association publications include the following:
    (1) CGA C-1, Methods for Pressure Testing Compressed Gas Cylinders
(2016). During the open comment period of this NPRM, this publication
is freely available on the CGA Web site at: https://www.cganet.com/customer/dot.aspx. This publication provides the standard(s) for
pressure testing of compressed gas cylinders for many newly
manufactured cylinders and requalification of cylinders. This standard
contains operating and equipment requirements necessary to perform
pressure testing of compressed gas cylinders properly. Tests include
the water jacket method, direct expansion method, and proof pressure
method.
    (2) CGA C-3, Standards for Welding on Thin-Walled Steel Cylinders
(2005) (Reaffirmed 2011). During the open comment period of this NPRM,
this publication is freely available on the CGA Web site at: https://www.cganet.com/customer/dot.aspx. This publication contains information
on welding process qualification, welding operator qualifications,
tensile testing, bend testing, and radiographic inspection.
Additionally, this publication clarifies dimensional tolerances and
when weld macro etch can be used for weld process approval and welder
qualification approval.
    (3) CGA C-6, Standards for Visual Inspection of Steel Compressed
Gas Cylinders (2013). During the open comment period of this NPRM, this
publication is freely available on the CGA Web site at: https://www.cganet.com/customer/dot.aspx. This publication provides cylinder
users (requalifiers, owners, fillers, operators, etc.) with criteria to
accept, reject, and condemn steel compressed gas cylinders. This
standard does not cover all circumstances for each individual cylinder
type and condition of lading. Inspection procedures include preparation
of cylinders for inspection, exterior inspection, interior inspection
(if required), nature and extent of damage to be looked for, and for
some tests, the conditions of the cylinder, etc. A sample inspection
report is provided in an appendix.
    (4) CGA C-14, Procedures for Fire Testing of DOT Cylinder Pressure
Relief Device Systems (2005) (Reaffirmed 2010). During the open comment
period of this NPRM, this publication is freely available on the CGA
Web site at: https://www.cganet.com/customer/dot.aspx. This publication
describes test procedures and apparatus for fire testing compressed gas
cylinder safety (pressure) relief devices as required by the HMR. The
procedures are applicable for cylinders that are less than 500 lbs.
water capacity and designed to provide a means of testing to the HMR
anywhere with reliable test data and repeatable test results.
    (5) CGA S-1.1, Pressure Relief Device Standards--Part 1--Cylinders
for Compressed Gases (2011). During the open comment period of this
NPRM, this publication is freely available on the CGA Web site at:
https://www.cganet.com/customer/dot.aspx. This publication provides the
standard(s) for selection of the correct pressure relief device that is
required to meet the requirements of the HMR for over 150 gases. It
provides guidance on when a pressure relief device can be optionally
omitted, and when the use of a pressure relief device is prohibited. It
provides direction and guidance on the manufacture and testing of
pressure relief devices as well as the operation parameters and
maintenance.

Section 171.23

    Section 171.23 prescribes requirements for transport of specific
materials and packaging under international transportation standards
such as the International Civil Aviation Organization Technical
Instructions for the Safe Transport of Dangerous Goods by Air.
Paragraph (a)(4) outlines requirements for filling of cylinders for
export or use onboard a vessel. In this NPRM, we propose to revise the
marking requirements consistent with changes made to Sec.  180.213.

Section 172.400a

    Section 172.400a(a)(1) prescribes exceptions from labeling for
Dewar flasks or cylinders that comply with the provisions of this
paragraph and are durably marked and labeled in conformance with CGA C-
7. In this NPRM, we propose to revise paragraph (a)(1) to clarify how
this labeling exception applies to overpacks.

Section 173.3

    Section 173.3(d)(1) prescribes how a damaged or leaking cylinder
that contains hazardous material may be transported in a non-DOT-
specification fully opening hinged-head or removable head steel salvage
cylinder. In this NPRM, we propose to permit cylinders that contain
Class 4 or 5 materials to also use this exception. In addition, because
of the proposal to include Class 4 or 5 materials as authorized
material for salvage cylinders, we are reformatting the regulatory text
to reference those materials in damaged or leaked cylinders that are
excluded from being allowed to be overpacked in a salvage cylinder
rather than listing those that are authorized.

Section 173.301

    Section 173.301 provides the general requirements for shipment of
compressed gases and other hazardous material in cylinders. In this
NPRM, we propose to clarify the marking requirements of paragraph
(a)(9), specifically use of the ``OVERPACK'' mark to indicate the
combination packaging contains inner packagings that conform to
specifications. Additionally, in paragraphs (c) and (f), we propose an
editorial revision to the section citation of CGA S-1.1 to correctly
read 9.1.1. Finally, we propose to revise paragraph (f) to clarify the
minimum burst pressure requirements for DOT 39 cylinders used to
transport compressed or liquefied oxidizing gases.

Section 173.302

    Section 173.302(a)(2) prescribes the requirements for adsorbed
gases. In this NPRM, we propose to include references to new Sec.
173.302d applicable to DOT-specification cylinders and to replace
reference to ``UN cylinders'' with ``UN pressure receptacles'' for
consistency with other parts of the HMR.

Section 173.302a

    Section 173.302a(a)(3) prescribes the filling requirements for DOT
39 cylinders that contain Division 2.1 gas or chemical under pressure.
In this NPRM, we propose to clarify the capacity (internal volume)
requirements to make it clear that the 1.23 L limit applies to Division
2.1 material and the 50 L limit applies to chemical under pressure
classed as Division 2.1 (see Sec.  172.102, special provision 362). We
also propose an editorial correction to the start of paragraph (a)(3)
by removing the non-italicized ``DOT 39.''

Section 173.302d

    In this NPRM, we propose to add new Sec.  173.302d prescribing
requirements for transportation of adsorbed gases in DOT-specification
cylinders. The requirements of this new section are based on the
adoption of special permit DOT-SP 14237 provisions.

Section 173.304a

    Section 173.304a prescribes the maximum permitted filling density
and authorized cylinders for specific gases. In this NPRM, we propose
to add new paragraph (a)(3) to Sec.  173.304a to clearly state that the
maximum capacity (internal volume) of a DOT 39 cylinder containing
liquefied flammable gas is 1.23 liters (75 in\3\). We also propose to
require these cylinders to be equipped with a pressure relief valve, as
prescribed in CGA S-1.1, unless the material is not listed in CGA S-
1.1, in which case a CG-7 pressure relief valve must be used.

Section 173.306

    Section 173.306 provides exceptions from the requirements of the
HMR for limited quantities of compressed gas. Paragraph (g) excepts
water pump system tanks charged with compressed air or limited
quantities of nitrogen to not over 40 psig from labeling and
specification packaging when shipped in conformance with the
requirements prescribed in the paragraph. In this NPRM, we propose to
revise Sec.  173.306(g) to authorize tanks to be tested to current
standards in the HMR or the manufacturer's specified maximum working
pressure, to allow water pump system tanks to be charged with helium,
to clarify that transportation by aircraft is not an authorized mode of
transport.

Section 173.309

    In this NPRM, we propose to revise Sec.  173.309 to state that the
requirements applicable to fire extinguishers also apply to those
cylinders used as part of a fire suppression system.

Section 173.312

    Section 173.312(b)(1) prescribes the filling requirements for
multiple element gas containers (MEGCs). In this NPRM, we propose
requirements for filling pressure receptacles containing liquefied
compressed gas by weight.

Section 178.35

    Section 178.35(f) prescribes the marking requirements that apply to
DOT-specification cylinders. In this NPRM, we propose to add new
paragraph (f)(7) to Sec.  178.35 to require that cylinder tare weight
or mass weight, and water capacity, be marked on certain DOT-
specification cylinders filled by weight.

Sections 178.36, 178.37, 178.38, 178.39, 178.42, 178.44, 178.45,
178.46, 178.47, 178.50, 178.51, 178.53, 178.55 178.56, 178.57, 178.58,
178.59, 178.60, 178.61, 178.65, and 178.68

    These sections prescribe the DOT-specification requirements for a
cylinder type including the performance standards for pressure testing
of the cylinder. In this NPRM, we propose to require that testing and
equipment used to conduct the pressure testing be in conformance with
CGA C-1, Methods for Pressure Testing Compressed Gas Cylinders, to
provide for consistency and clarity in performance of pressure testing.
We also propose to revise the format of the pressure testing paragraphs
for greater consistency.

Sections 178.50, 178.51, 178.61, and 178.68

    These sections prescribe DOT 4-series specification requirements.
These specifications are often unclear to manufacturers and enforcement
personnel. In this NPRM, we propose to revise the specification
requirements to promote consistent and uniform manufacturing practices
for DOT 4-series cylinders.

Section 178.70

    Section 178.70(d) prescribes the requirements to obtain design
approval of a UN pressure receptacle. In this NPRM, we propose to
revise paragraph (d) to include language that an approval for a design
modification is not required if the specific design modification is

covered under the UN/ISO standard for the design type already approved.

Section 180.203

    Section 180.203 prescribes definitions that apply to the
qualification, maintenance, and use of cylinders under the HMR. In this
NPRM, we propose to add new definitions for the terms or phrases
``accuracy,'' ``accuracy grade,'' ``actual test pressure,''
``calibrated cylinder,'' ``error,'' ``master gauge,'' ``mobile unit,''
``overpressurized,'' ``percent permanent expansion,'' ``precision,''
``proof pressure test,'' ``reference gauge,'' and ``service pressure'';
and revise the definitions for ``commercially free of corrosive
components,'' ``defect,'' and ``test pressure.'' These proposed
definitions will clarify the cylinder requirements prescribed in 49 CFR
part 180, subpart C.

Section 180.205

    Section 180.205 prescribes the general requirements for
requalifying DOT-specification cylinders. In this NPRM, we propose to
revise and add new regulatory text for clarity. Specifically, we
propose to clarify the conditions requiring test and inspection of
cylinders under paragraph (d) by including a reference to evidence of
grinding; revise the paragraph (f) visual inspection requirements to
include reference to shot blasting and ``chasing'' of cylinders;
clarify and revise the paragraph (g) retest equipment tolerances for
consistency with ISO standards 6406 and 10461 (i.e., standards for
periodic inspection and testing of gas cylinders) which are both
incorporated by reference in the HMR in Sec.  180.207 to allow for
broader use of retest equipment (we invite comment on this course of
action relative to the tolerances provided for in CGA C-1); revise the
paragraph (i) cylinder condemnation requirements to clarify the
responsibilities of the requalifier and add conditions under which a
cylinder must be condemned; and include a reference to training
materials, under new paragraph (j), that are suitable for training
persons who requalify cylinders using the volumetric expansion test
method.

Section 180.207

    Section 180.207 prescribes requirements for requalifying UN
pressure receptacles. In this NPRM, we propose to revise and add new
regulatory text for clarity. Specifically, we propose to clarify the
language prohibiting the use of a UN pressure receptacle beyond its
service life by, for example, removing approval authorization language;
to revise the requalification procedures for seamless steel cylinders
to include MEGC pressure receptacles larger than 150 liters water
capacity; and to revise the requalification schedule for dissolved
acetylene UN cylinders to be requalified no sooner than five years and
no later than ten years from the date of manufacture.

Section 180.209

    Section 180.209 prescribes requirements for requalifying
specification cylinders. In this NPRM, we propose to revise and add new
regulatory text for clarity; and to incorporate the current version of
CGA C-1, Methods for Pressure Testing Compressed Gas Cylinders.
Specifically, we propose to revise the paragraph (a) table 1 to include
reference to the paragraph (e) conditions for an alternate
requalification period; the paragraph (b) conditions for star-marking
of a DOT 3A or 3AA cylinder; and the paragraph (m) requalification
conditions for DOT 3AL cylinders made of 6351-T6 aluminum alloy.

Section 180.211

    Section 180.211 prescribes requirements to repair, rebuild, and
reheat treat DOT-4 series specification cylinders. In this NPRM, we
propose to clarify that the requirements to repair DOT 4L cylinders in
paragraph (c) of this section are for rebuilding the cylinders and to
clarify paragraph (e) for when a hydrostatic test may be performed on
the inner containment vessel of a DOT 4L welded insulated cylinder. We
do not propose in this NPRM to add a definition for ``recondition'' to
Sec.  180.203 because of our concern that adding this definition for
only DOT 4L cylinders might cause further confusion and reduce safety.

Section 180.212

    Section 180.212(a) prescribes requirements to repair seamless DOT
3-series specification cylinders and seamless UN pressure receptacles.
In this NPRM, we propose to require an ultrasonic examination on DOT 3-
series cylinders and seamless UN pressure receptacles after any
grinding is performed on these cylinders.

Section 180.213

    Section 180.213 prescribes requirements for marking DOT-
specification cylinders and UN pressure receptacles that are
successfully requalified. In this NPRM, we propose to revise the
requalification marking method to clarify the steps involved and that
stamping the sidewall of the cylinder is prohibited. Additionally, we
propose to clarify the marking requirements for foreign cylinders
filled for export under paragraph (d) and to include two new marking
requirements under paragraph (f) for designation of grinding with
ultrasonic wall thickness examination and for designation of
requalification of a foreign cylinder requalified in conformance with
Sec. Sec.  171.23(a)(4) and 180.209(l) of this subchapter. Finally, we
propose to add visual inspection identifier number marking requirements
under a new paragraph (g).

Section 180.215

    Section 180.215 prescribes reporting and retention requirements for
a person who requalifies, repairs, or rebuilds cylinders. In this NPRM,
we propose to clarify what information these documents must contain.

49 CFR Part 180, Appendix C

    Part 180, appendix C prescribes the requirements eddy current
examination equipment must meet to inspect DOT 3AL, 6351-T6 aluminum
alloy cylinders. In this NPRM, we propose to retitle the appendix and
revise paragraph 1 for clarity regarding equipment calibration
procedures when conducting eddy current examination.

VII. Regulatory Analyses and Notices

A. Statutory/Legal Authority for This NPRM

    Federal Hazardous Materials Transportation Law (49 U.S.C. 5101-
5128) authorizes the Secretary of Transportation to ``prescribe
regulations for the safe transportation, including security, of
hazardous material in intrastate, interstate, and foreign commerce.''
Section 5117(a) authorizes the Secretary to issue a special permit
exempting compliance with a regulation prescribed in Sec. Sec.
5103(b), 5104, 5110, or 5112 ``to a person transporting, or causing to
be transported, hazardous material in a way that achieves a safety
level at least equal to the safety level required under [the Federal
hazmat law], or consistent with the public interest . . . if a required
safety level does not exist.'' The issues described in this NPRM
respond to 20 outstanding petitions for rulemaking.

B. Executive Order 12866, Executive Order 13563, and DOT Regulatory
Policies and Procedures

    This NPRM is not considered a significant regulatory action under
section 3(f) of Executive Order 12866 (``Regulatory Planning and
Review'') and was not reviewed by the Office of Management and Budget
(OMB).

Neither was it considered a significant rule under the Regulatory
Policies and Procedures order issued by the Department of
Transportation [44 FR 11034].
    Executive Order 13563 (``Improving Regulation and Regulatory
Review'') is ``supplemental to and reaffirms the principles,
structures, and definitions governing regulatory review that were
established in Executive Order 12866 of September 30, 1993.'' In
addition, Executive Order 13563 specifically requires agencies to: (1)
Involve the public in the regulatory process; (2) promote
simplification and harmonization through interagency coordination; (3)
``identify and consider regulatory approaches that reduce burdens and
maintain flexibility''; (4) ensure the objectivity of any scientific or
technological information used to support regulatory action; and (5)
consider how to best promote retrospective analysis to modify,
streamline, expand, or repeal existing rules that are outmoded,
ineffective, insufficient, or excessively burdensome.
    PHMSA has involved the public in the regulatory process by (1)
addressing issues identified for possible future rulemaking in letters
of interpretation and other correspondence, and (2) responding to 20
petitions for rulemaking submitted by stakeholders in the compressed
gas industry in conformance with 49 CFR 106.95. Overall, the issues
discussed in this NPRM promote the continued safe transportation of
hazardous materials while producing a net benefit.
    These petitions clarify the existing regulatory text in the HMR,
incorporate widely used industry publications, and address specific
safety concerns, thus enhancing the safe transportation of compressed
gases while limiting the impact on the regulated community.
Incorporating the provisions of special permits into regulations with
general applicability will provide shippers and carriers with
additional flexibility to comply with established safety requirements,
thereby reducing burdens and costs and increasing productivity.
    Further, PHMSA on its own initiative is clarifying existing
regulatory language to reduce misunderstandings that will thereby
improve safety. Some of the proposed changes are summarized below, by
topic.
Incorporating Updated CGA C-6, Visual Inspection of Steel Cylinders
    PHMSA proposes to replace the currently incorporated Seventh
Edition of the CGA publication C-6, Standards for Visual Inspection of
Steel Compressed Gas Cylinders with the revised Eleventh Edition and
update the appropriate references throughout the HMR.
    Under the HMR, compressed gas cylinders must be visually inspected
as part of the requalification process once every five years. CGA C-6
serves as a guide to cylinder requalifiers and users for establishing
cylinder inspection procedures and standards. The Tenth Edition
provides updated and enhanced guidance on the inspection of multi-
element gas containers, cylinder thread inspection for cylinders used
in corrosive gas service, and clarified maximum allowable depths and
measuring techniques for various types of corrosion.
    PHMSA identified approximately 5,000 companies that would be
subject to this standard. The majority of these companies are
classified as small businesses using SBA size standards. This revision
would impose a one-time individual cost for purchase of the updated
standard. We assume that the majority of companies subject to this
standard are non-CGA members or non-CGA subscribers. Assuming
approximately 5,000 companies purchase the Eleventh Edition of CGA-6,
we estimate the upper bound of the total cost across all affected
entities for this proposal would be approximately $710,000.
    The benefit of this change is that it would improve the clarity of
industry standards that are currently incorporated by reference. It
facilitates voluntary compliance and reduces the burdens associated
with references to outdated material. PHMSA believes that these changes
may yield an incremental improvement to the overall safety of hazmat
cylinder transportation. In comments made to the ANPRM, five
stakeholders support the proposal to update the IBR of CGA C-6 to the
Tenth Edition. No commenters objected to the proposal or provided
benefit data.
Incorporating CGA C-1 Methods of Pressure Testing Compressed Gas
Cylinders Into the HMR
    PHMSA proposes to revise the HMR regarding the retesting of
cylinders using pressure testing. The HMR is often perceived as unclear
on procedures and requirements for pressure testing of cylinders.
Incorporating by reference CGA C-1, Methods for Pressure Testing
Compressed Gas Cylinders clarifies ambiguities in the HMR.
    It is estimated that this would affect approximately 980 entities
that conduct pressure testing, including cylinder requalifiers,
retesters, and manufacturers. PHMSA estimates a one-time compliance
cost of $186 for each entity purchasing the Eleventh Edition of CGA C-
1. The upper bound of the total cost across all affected entities for
this proposal would be approximately $182,280. Actual costs are
expected to be lower, as some of the 980 entities may be members,
subscribers, or already own the revised edition. Revising the HMR to
incorporate CGA C-1 would increase clarity, reduce confusion, provide
enhanced guidance, and provide marginal safety benefits without
imposing requirements that are potentially costly or difficult.
Weight Marking Requirements for Filling of DOT 4-Series Specification
Cylinders
    PHMSA proposes to require newly manufactured DOT 4B, 4BA, 4BW, and
4E cylinders to be marked with the tare weight or the mass weight and
the water capacity. Accurate cylinder tare weight, or mass weight, and
water capacity are crucial for safe filling and transportation of
cylinders containing liquefied compressed gas. Overfilled cylinders
have the potential for leakage and possible failure during transport.
    PHMSA identified six U.S. based manufacturers of the cylinders.
Five of these companies are classed as small businesses using SBA size
standards. The HMR already incorporate by reference NFPA 58, LP Gas
Code, which requires cylinders used for liquefied petroleum gases to be
marked with the tare weight and water capacity. The NFPA 58 does not
specify how the cylinders must be marked, nor does it specify by whom.
Further, NFPA 58 only addresses liquefied petroleum gas, not all
liquefied compressed gases. We do not anticipate significant additional
costs to DOT 4-series-specification cylinders, manufacturers, or
owners, because many in the liquefied compressed gas industry already
request that manufacturers mark cylinders with this additional
information as an added safety measure.
Clarify Filling Limits on Multiple Element Gas Containers
    PHMSA proposes to clarify filling limits for a liquefied compressed
gas in a manifold comprised of DOT-specification cylinders or a
multiple element gas container (MEGC). Specifically, liquefied
compressed gases contained in manifold cylinders cannot exceed the
filling densities specified in Sec.  173.304a(a)(2) and liquefied gases
in MEGCs comprised of UN pressure receptacles must not exceed the
values contained in P200 as specified in Sec.  173.304b.
    This proposed change will remove the discrepancy between the set
pressure

specified in CGA S-1.1 and the differing set pressures prescribed in
Sec. Sec.  173.302(f)(2) and 173.304(f)(2). This revision would not
impose any new costs on affected industries, and although the proposed
revision restates a requirement from another section in the HMR, we
believe it would provide additional protection against overfilling of a
cylinder. This change would promote regulatory compliance and foster
safe filling practices.

C. Executive Order 13132

    This proposed rule has been analyzed in accordance with the
principles and criteria contained in Executive Order 13132
(``Federalism'') and the President's memorandum (``Preemption'') that
was published in the Federal Register on May 22, 2009 [74 FR 24693].
This proposed rule will preempt State, local, and Native America tribal
requirements but does not propose any regulation that has substantial
direct effects on the States, the relationship between the national
government and the States, or the distribution of power and
responsibilities among the various levels of government. Therefore, the
consultation and funding requirements of Executive Order 13132 do not
apply.
    The Federal Hazardous Materials Transportation Law, 49 U.S.C. 5101-
5128, contains an express preemption provision [49 U.S.C. 5125 (b)]
that preempts State, local, and Native American tribal requirements on
the following subjects:
    (1) The designation, description, and classification of hazardous
materials;
    (2) The packing, repacking, handling, labeling, marking, and
placarding of hazardous materials;
    (3) The preparation, execution, and use of shipping documents
related to hazardous materials and requirements related to the number,
contents, and placement of those documents;
    (4) The written notification, recording, and reporting of the
unintentional release in transportation of hazardous material; and
    (5) The design, manufacture, fabrication, marking, maintenance,
recondition, repair, or testing of a packaging or container
represented, marked, certified, or sold as qualified for use in
transporting hazardous material.
    PHMSA invites those with an interest in the issues presented in
this NPRM to comment on the effect the adoption of specific proposals
may have on State or local governments.

D. Executive Order 13175

    This NPRM was analyzed in accordance with the principles and
criteria contained in Executive Order 13175 (``Consultation and
Coordination with Indian Tribal Governments''). Because this NPRM does
not have tribal implications and does not impose substantial direct
compliance costs on Native American tribal governments, the funding and
consultation requirements of Executive Order 13175 do not apply, and a
tribal summary impact statement is not required. We invite Native
American tribal governments to provide comments on the effect the
adoption of specific proposals may have on Indian communities.

E. Regulatory Flexibility Act, Executive Order 13272, and DOT
Procedures and Policies

    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 impact on a substantial number of small entities. The term
``small entities'' comprises small businesses and not-for-profit
organizations that are independently owned and operated and are not
dominant in their fields and governmental jurisdictions with
populations of less than 50,000. (See 5 U.S.C. 601.) This notice has
been developed in accordance with Executive Order 13272 (``Proper
Consideration of Small Entities in Agency Rulemaking'') and DOT's
Policies and Procedures to promote compliance with the Regulatory
Flexibility Act to ensure that potential impacts of draft rules on
small entities are properly considered. Section 603(b) of the
Regulatory Flexibility Act requires an analysis of the possible impact
of the proposed rule on small entities, including the need for the
rule, the description of the action, the identification of potentially
affected small entities, the reporting and recordkeeping requirements,
the related Federal rules and regulations, and the alternative
proposals considered. Such analysis for this NPRM is as follows:
1. Need for the NPRM
    Current requirements for the manufacture, use, and requalification
of cylinders can be traced to standards first applied in the early
1900s. Over the years, the regulations have been revised to reflect
advancements in transportation efficiency and changes in the national
and international economic environment. This NPRM is part of a
retrospective analysis to modify and streamline existing requirements
that are outmoded, ineffective, insufficient, or excessively
burdensome. This rulemaking also introduces new provisions suggested or
developed by industry representatives, industry groups that develop
standards, or international regulatory bodies.
2. Description of Action
    This NPRM considers incorporating the provisions of one special
permit, responds to 20 petitions for rulemaking, considers clarifying
other requirements in the HMR, and addresses areas of concern that are
currently left out of the HMR. The amendments discussed in this NPRM
are designed to increase flexibility for the regulated community,
promote technological advancement, and facilitate international
transportation while maintaining a comparable level of safety.
3. Identification of Potentially Affected Small Entities
    The amendments considered here are likely to affect cylinder
manufacturers (NAICS code 332420; approximately 568 companies);
cylinder requalifiers; independent inspection agencies; commercial
establishments that own and use DOT-specification cylinders and UN
pressure receptacles; and individuals who export non-UN/ISO compressed
gas cylinders (NAICS codes 32512, 336992, 423450, 423850, 423990,
454312, 541380). Nearly all of these companies, particularly cylinder
requalification facilities of which there are approximately 5,000, are
small entities based on the criteria developed by the Small Business
Administration.
4. Reporting and Recordkeeping Requirements
    This NPRM does not include any new reporting or recordkeeping
requirements.
5. Related Federal Rules and Regulations
    The Occupational Safety and Health Administration (OSHA) prescribes
requirements for the use, maintenance, and testing of portable fire
extinguishers in 29 CFR 1910.157 and requirements for fixed fire
suppression systems in 29 CFR 1910.160. The issues discussed in this
NPRM pertaining to the transportation of fire extinguishers and
compressed gas cylinders that are a component of a fixed fire
suppression system do not conflict with the requirements in 29 CFR.
With respect to the transportation of compressed gases in cylinders,
there are not related rules or regulations issued by other

departments or agencies of the Federal government.
6. Alternative Proposals for Small Business
    Certain regulatory actions may affect the competitive situation of
an individual company or group of companies by imposing relatively
greater burdens on small, rather than large, enterprises. PHMSA
requests comments from small entities on the impacts of these
additional requirements.
7. Conclusion
    This NPRM requests information that will be used to develop a
proposal to amend provisions of the HMR addressing the manufacture,
maintenance, and use of cylinders. PHMSA anticipates that the proposals
in this NPRM will reduce burdens for most persons and any costs
resulting from adoption of new requirements will be offset by the
benefits derived from eliminating the need to apply for special
permits, increasing regulatory flexibility, and improving safety
through enhanced compliance. If your business or organization is a
small entity and the adoption of the proposals contained in this NPRM
could have a significant economic impact on your operations, please
submit a comment explaining how and to what extent your business or
organization could be affected.

F. Paperwork Reduction Act

    This NPRM does not impose new information collection requirements.
Depending on the results of our request for comments to this NPRM,
there may be a decrease in the annual burden and costs under OMB-
proposed changes to incorporate provisions contained in certain widely
used or longstanding special permits with an established safety record.
    PHMSA specifically requests comments on the information collection
and recordkeeping burdens associated with developing, implementing, and
maintaining these requirements for approval under this NPRM.
    Address written comments to the Dockets Unit as identified in the
ADDRESSES section of this NPRM. We must receive comments regarding
information collection burdens prior to the close of the comment period
identified in the DATES section of this NPRM.

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

H. Unfunded Mandates Reform Act of 1995

    This NPRM does not impose unfunded mandates under the Unfunded
Mandates Reform Act of 1995. It does not result in costs of $141.3
million or more to either State, local, or tribal governments, in the
aggregate, or to the private sector and is the least burdensome
alternative that achieves the objective of the rule. Further, in
compliance with the Unfunded Mandates Reform Act of 1995, PHMSA will
evaluate any regulatory action that might be proposed in subsequent
stages of the proceeding to assess the effects on State, local, and
tribal governments and the private sector.

I. Environmental Assessment

    The National Environmental Policy Act of 1969 (NEPA), as amended
(42 U.S.C. 4321-4347), and implementing regulations by the Council on
Environmental Quality (CEQ) (40 CFR part 1500) require Federal agencies
to consider the consequences of major Federal actions and prepare a
detailed statement on actions that significantly affect the quality of
the human environment. The CEQ regulations require Federal agencies to
conduct an environmental review considering: (1) The need for the
proposed action; (2) alternatives to the proposed action; (3) probable
environmental impacts of the proposed action and alternatives; and (4)
the agencies and persons consulted during the consideration process.
1. Need for the Action
    This NPRM responds to 20 petitions for rulemaking submitted by the
regulated community and seeks comment on incorporating the provisions
of one special permit. The issues discussed in this NPRM would, if
eventually adopted, update and expand the use of currently authorized
industry consensus standards; revise the construction, marking, and
testing requirements of DOT 4-series cylinders; clarify the filling
requirements for cylinders; discuss the handling of cylinders used in
fire suppression systems; and revise the requalification and
condemnation requirements for cylinders.
    This NPRM discusses the following amendments to the HMR:
     Replace the currently incorporated Seventh Edition of the
CGA's publication C-6 Standards for Visual Inspection of Steel
Compressed Gas Cylinders with the revised Tenth Edition and update the
appropriate references throughout the HMR.
     Revise the manufacturing requirements for certain DOT-4
series cylinders.
     Revise the requirements for the requalification of DOT-
specification cylinders by pressure testing found in 49 CFR part 180,
subpart C.
     Allow the use of the labels described in the Eighth
Edition of CGA's publication C-7 Guide to the Preparation of
Precautionary Labeling and Marking of Compressed Gas Containers
(currently IBR in the HMR) appendix A on cylinders contained in
overpacks.
     Require manufacturers to mark newly manufactured cylinders
suitable for the transport of liquefied compressed gas with the mass
weight or tare weight, and water capacity.
     Allow non-specification cylinders used in a fixed fire
suppression system to be transported under the same exceptions as those
provided for fire extinguishers.
     Permit use of the OVERPACK marking for cylinders packed in
conformance with Sec.  173.301(a)(9).
     Clarify filling limits for a liquefied compressed gas in a
manifold or a multiple element gas container (MEGC).
     Clarify the requirements for filling non-specification
cylinders for export or use on board a vessel.
     Add requirements for DOT-specification cylinders used to
transport adsorbed gases.
2. Alternatives Considered
    Alternative (1): Do nothing. Our goal is to update, clarify, and
provide relief from certain existing regulatory requirements to promote
safer transportation practices, eliminate unnecessary regulatory
requirements, and facilitate international commerce. We rejected the
do-nothing alternative.
    Alternative (2): Preferred choice. With this alternative, PHMSA
will publish an NPRM seeking public comment on the issues raised in 20
petitions for rulemaking and the incorporation of one special permit;
review the comments received on the amendments described in the ANPRM
and their potential economic and safety implications; and use these
comments to craft more specific proposals that are published in this
NPRM. This is the selected alternative.

3. Environmental Impacts
    Hazardous materials are substances that may pose a threat to public
safety or the environment during transportation because of their
physical, chemical, or nuclear properties. The hazardous materials
regulatory system is a risk management system that is prevention-
oriented and focused on identifying a safety hazard and reducing the
probability and quantity of a hazardous material release. Hazardous
materials are categorized by hazard analysis and experience into hazard
classes and packing groups. The regulations require each shipper to
classify a material in accordance with these hazard classes and packing
groups. The process of classifying a hazardous material is itself a
form of hazard analysis. Further, the regulations require the shipper
to communicate a material's hazards through the use of hazard class,
packing group, and proper shipping name on the shipping paper and the
use of labels on packages and placards on transport vehicles. Thus, the
shipping paper, labels, and placards communicate the most significant
findings of the shipper's hazard analysis. A hazardous material is
assigned to one of three packing groups based upon its degree of
hazard, from a high hazard material (Packing Group I) to a low hazard
material (Packing Group III). The quality, damage resistance, and
performance standards of the packaging in each packing group are
appropriate for the hazards of the material transported.
    Under the HMR, hazardous materials are transported by aircraft,
vessel, rail, and highway. The potential for environmental damage or
contamination exists when packages of hazardous materials are involved
in accidents or en route incidents resulting from cargo shifts, valve
failures, package failures, loading, unloading, collisions, handling
problems, or deliberate sabotage. The release of hazardous materials
can cause the loss of ecological resources (e.g., wildlife habitats)
and the contamination of air, aquatic environments, and soil.
Contamination of soil can lead to the contamination of ground water.
Compliance with the HMR substantially reduces the possibility of
accidental release of hazardous materials.
    It is anticipated that the petitions and special permits discussed
in this NPRM if adopted in a future rulemaking, would have minimal, if
any, environmental consequences.
4. Agencies Consulted
Occupational Safety and Health Administration
National Institute of Standards and Technology
U.S. Environmental Protection Agency
5. Conclusion
    PHMSA has conducted a technical review of the amendments discussed
in this NPRM and determined that the amendments considered would
provide protection against the release of hazardous materials based on
sound scientific methods and would not result in unusual stresses on
the cylinder or adversely impact human health or the environment. PHMSA
welcomes any data or information related to environmental impacts, both
positive and negative, that may result from a future rulemaking
addressing the issues discussed in this NPRM.

J. Privacy Act

    In accordance with 5 U.S.C. 553(c), DOT solicits comments from the
public to better inform its rulemaking process. DOT posts these
comments, without edit, including any personal information the
commenter provides, to www.regulations.gov, as described in the system
of records notice (DOT/ALL-14 FDMS), which can be reviewed at
www.dot.gov/privacy.

K. International Trade Analysis

    The Trade Agreements Act of 1979 (Pub. L. 96-39), as amended by the
Uruguay Round Agreements Act (Pub. L. 103-465), prohibits Federal
agencies from establishing any standards or engaging in related
activities that create unnecessary obstacles to the foreign commerce of
the United States. Pursuant to these Acts, the establishment of
standards is not considered an unnecessary obstacle to the foreign
commerce of the United States, so long as the standards have a
legitimate domestic objective, such as the protection of safety, and do
not operate in a manner that excludes imports that meet this objective.
The statute also requires consideration of international standards and,
where appropriate, that they be the basis for U.S. standards. PHMSA
notes the purpose is to ensure the safety of the American public and
has assessed the effects of this NPRM to ensure that it does not
exclude imports that meet this objective. As a result, this NPRM is not
considered as creating an unnecessary obstacle to foreign commerce.

List of Subjects

49 CFR Part 107

    Administrative practice and procedure, Hazardous materials
transportation, 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

    Education, Hazardous materials transportation, Hazardous waste,
Incorporation by reference, Labeling, Markings, Packaging and
containers, Reporting and recordkeeping requirements.

49 CFR Part 173

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

49 CFR Part 178

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

49 CFR Part 180

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

    In consideration of the foregoing, PHMSA is proposing to amend 49
CFR Chapter I as follows:

PART 107--HAZARDOUS MATERIALS PROGRAM PROCEDURES

0
1. The authority citation for part 107 continues to read as follows:

    Authority:  49 U.S.C. 5101-5128, 44701; Pub. L. 101-410 section
4 (28 U.S.C. 2461 note); Pub. L. 104-121, sections 212-213; Pub. L.
104-134, section 31001; Pub. L. 112-141 section 33006; 49 CFR 1.81
and 1.97.

0
2. In Sec.  107.803, revise paragraph (c)(3) to read as follows:

Sec.  107.803  Approval of an independent inspection agency (IIA).

* * * * *
    (c) * * *
    (3) Detailed description of the applicant's qualifications and
ability to perform the inspections and to verify the inspections
required by part 178 and part 180 of this chapter; or those required
under the terms of a special permit issued under this part.
* * * * *
0
3. In Sec.  107.805, revise paragraphs (c)(3) and (c)(4), and add
paragraph (c)(5) to read as follows:

Sec.  107.805  Approval of cylinder and pressure receptacle
requalifiers.

* * * * *
    (c) * * *
    (3) A certification that the facility will operate in compliance
with the applicable requirements of subchapter C of this chapter;
    (4) The signature of the person making the certification and the
date on which it was signed; and
    (5) For a mobile unit operation (as defined in Sec.  180.203 of
subchapter C of this chapter), the type of equipment to be used, the
specific vehicles to be used, the geographic area the applicant is
requesting to operate within, and any differences between the mobile
operation and the facility operation as described under paragraph
(c)(2) of this section.
* * * * *

PART 171--GENERAL INFORMATION, REGULATIONS, AND DEFINITIONS

0
4. The authority citation for part 171 continues to read as follows:

    Authority:  49 U.S.C. 5101-5128, 44701; Pub. L. 101-410 section
4 (28 U.S.C. 2461 note); Pub. L. 104-121, sections 212-213; Pub. L.
104-134, section 31001; 49 CFR 1.81 and 1.97.

0
5. In Sec.  171.7, revise paragraphs (g)(1) and (n) to read as follows:

Sec.  171.7  Reference material.

* * * * *
    (g) * * *
    (1) 2015 ASME Boiler and Pressure Vessel Code (ASME Code), 2015
Edition, July 1, 2015 (as follows), into Sec. Sec.  172.102; 173.3;
173.5b; 173.24b; 173.302d; 173.306; 173.315; 173.318; 173.420; 178.255-
1; 178.255-2; 178.255-14; 178.255-15; 178.273; 178.274; 178.276;
178.277; 178.320; 178.337-1; 178.337-2; 178.337-3; 178.337-4; 178.337-
6; 178.337-16; 178.337-18; 178.338-1; 178.338-2; 178.338-3; 178.338-4;
178.338-5; 178.338-6; 178.338-13; 178.338-16; 178.338-18; 178.338-19;
178.345-1; 178.345-2; 178.345-3; 178.345-4; 178.345-7; 178.345-14;
178.345-15; 178.346-1; 178.347-1; 178.348-1; 179.400-3; 180.407.
* * * * *
    (n) Compressed Gas Association (CGA), 1235 Jefferson Davis Highway,
Arlington, VA 22202.
    (1) CGA C-1, Methods for Pressure Testing Compressed Gas Cylinders,
2016, into Sec. Sec.  178.36, 178.37, 178.38, 178.39, 178.42, 178.44,
178.45, 178.46, 178.47; 178.50; 178.51; 178.53; 178.55; 178.56; 178.57;
178.58; 178.59; 178.60; 178.61; 178.65; 178.68; 180.205, 180.209.
    (2) CGA C-3, Standards for Welding on Thin-Walled Steel Cylinders,
2005 (Reaffirmed 2011), into Sec. Sec.  178.47; 178.50; 178.51; 178.53;
178.55; 178.56; 178.57; 178.58; 178.59; 178.60; 178.61; 178.65; 178.68;
180.211.
    (3) CGA C-5, Cylinder Service Life--Seamless Steel High Pressure
Cylinders, 1991 (Reaffirmed 1995), into Sec.  173.302a and 180.209.
    (4) CGA C-6, Standards for Visual Inspection of Steel Compressed
Gas Cylinders, 2013, into Sec. Sec.  172.102, 173.3, 173.198, 173.302d,
180.205, 180.209, 180.211, 180.411, 180.519.
    (5) CGA C-6.1, Standards for Visual Inspection of High Pressure
Aluminum Compressed Gas Cylinders, 2002, into Sec. Sec.  180.205;
180.209.
    (6) CGA C-6.2, Guidelines for Visual Inspection and Requalification
of Fiber Reinforced High Pressure Cylinders, 1996, into Sec.  180.205.
    (7) CGA C-6.3, Guidelines for Visual Inspection and Requalification
of Low Pressure Aluminum Compressed Gas Cylinders, 1991, into
Sec. Sec.  180.205; 180.209.
    (8) CGA C-7, Guide to Preparation of Precautionary Labeling and
Marking of Compressed Gas Containers, Appendix A, issued 2004, into
Sec.  172.400a.
    (9) CGA C-8, Standard for Requalification of DOT-3HT Cylinder
Design, 1985, into Sec. Sec.  180.205; 180.209.
    (10) CGA C-11, Recommended Practices for Inspection of Compressed
Gas Cylinders at Time of Manufacture, 2001, into Sec.  178.35.
    (11) CGA C-12, Qualification Procedure for Acetylene Cylinder
Design, 1994, into Sec. Sec.  173.301; 173.303; 178.59; 178.60.
    (12) CGA C-13, Guidelines for Periodic Visual Inspection and
Requalification of Acetylene Cylinders, 2000, into Sec. Sec.  173.303;
180.205; 180.209.
    (13) CGA C-14, Procedures for Fire Testing of DOT Cylinder Pressure
Relief Device Systems, 2005 (Reaffirmed 2010), into Sec. Sec.  173.301;
173.323.
    (14) CGA G-1.6, Standard for Mobile Acetylene Trailer Systems,
2011, in Sec.  173.301(g).
    (15) CGA G-2.2, Guideline Method for Determining Minimum of 0.2%
Water in Anhydrous Ammonia, 1985, Reaffirmed 1997, into Sec.  173.315.
    (16) CGA G-4.1, Cleaning Equipment for Oxygen Service, 1985, into
Sec.  178.338-15.
    (17) CGA P-20, Standard for the Classification of Toxic Gas
Mixtures, 2003, Third Edition, into Sec.  173.115.
    (18) CGA S-1.1, Pressure Relief Device Standards--Part 1--Cylinders
for Compressed Gases, (except paragraph 9.1.1), 2011, into Sec. Sec.
173.301; 173.304a; 178.75.
    (19) CGA S-1.2, Safety Relief Device Standards Part 2--Cargo and
Portable Tanks for Compressed Gases, 1980, into Sec. Sec.  173.315;
173.318; 178.276; 178.277.
    (20) CGA S-7, Method for Selecting Pressure Relief Devices for
Compressed Gas Mixtures in Cylinders, 2005, into Sec.  173.301.
    (21) CGA TB-2, Guidelines for Inspection and Repair of MC-330 and
MC-331 Cargo Tanks, 1980, into Sec. Sec.  180.407; 180.413.
    (22) CGA TB-25, Design Considerations for Tube Trailers, 2008, into
Sec.  173.301.
* * * * *
0
6. In Sec.  171.23, revise paragraph (a)(4)(i) to read as follows:

Sec.  171.23  Requirements for specific materials and packagings
transported under the ICAO Technical Instructions, IMDG Code, Transport
Canada TDG Regulations, or the IAEA Regulations.

* * * * *
    (a) * * *
    (4) * * *
    (i) The cylinder has been requalified and marked in accordance with
subpart C of part 180 of this subchapter, or has been requalified as
authorized by the Associate Administrator;
* * * * *

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

0
7. The authority citation for part 172 continues to read as follows:

    Authority:  49 U.S.C. 5101-5128, 44701; 49 CFR 1.81, 1.96 and
1.97.

0
8. In Sec.  172.400a, revise paragraph (a)(1) to read as follows:

Sec.  172.400a  Exceptions from labeling.

* * * * *
    (a) * * *
    (1) A Dewar flask meeting the requirements in Sec.  173.320 of this
subchapter, or a cylinder containing a Division 2.1, 2.2, or 2.3
material, that is durably and legibly marked in conformance with CGA C-
7, appendix A (IBR; see Sec.  171.7 of this subchapter). However, if
overpacked, marking (or appropriate labels) must be communicated on the
exterior of the overpack unless visible from the outside in accordance
with Sec.  173.25 of this subchapter.
* * * * *

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

0
9. The authority citation for part 173 continues to read as follows:

    Authority:  49 U.S.C. 5101-5128, 44701; 49 CFR 1.81, 1.96 and
1.97.

0
10. In Sec.  173.3, revise paragraph (d)(1) to read as follows:

Sec.  173.3  Packaging and exceptions.

* * * * *
    (d) * * *
    (1) Except for Class 1, Class 7, or acetylene material, a cylinder
containing a hazardous material may be overpacked in a salvage
cylinder.
* * * * *
0
11. In Sec.  173.301:
0
a. Revise paragraphs (a)(9) and (f)(4); and
0
b. In paragraphs (c) and (f), replace ``<IP_ADDRESS>'' with ``9.1.1'' in
each place it appears.
    The revision reads as follows:

Sec.  173.301  General requirements for shipment of compressed gases
and other hazardous materials in cylinders, UN pressure receptacles and
spherical pressure vessels.

    (a) * * *
    (9) Specification 2P, 2Q, 3E, 3HT, spherical 4BA, 4D, 4DA, 4DS, and
39 cylinders must be packed in strong non-bulk outer packagings. The
outside of the combination package must be marked with an indication
that the inner packagings conform to the prescribed specifications.
Except for Specification 2P and 2Q containers, the ``OVERPACK'' marking
in accordance with Sec.  173.25(a)(3) of this part may be used to
satisfy the marking requirement of this paragraph. Display of the
``OVERPACK'' marking is not an indication that this combination package
is an overpack.
* * * * *
    (f) * * *
    (4) DOT 39 cylinders. (i) A pressure relief device is required on a
DOT 39 cylinder regardless of cylinder size or filled pressure.
    (ii) A DOT 39 cylinder used for liquefied Division 2.1 materials
must be equipped with a metal pressure relief device.
    (iii) Fusible pressure relief devices are not authorized on a DOT
39 cylinder containing a liquefied gas.
    (iv) Notwithstanding the requirements of paragraph (f)(1) of this
section with respect to the minimum burst pressure of pressure relief
devices, a pressure relief device on a DOT 39 cylinder used to
transport compressed or liquefied oxidizing gases may have a minimum
burst pressure within the range prescribed in Sec. Sec.  173.302(f)(2)
or 173.304(f)(2), as appropriate.''
* * * * *
0
12. In Sec.  173.302, revise paragraph (a)(2) to read as follows:

Sec.  173.302  Filling of cylinders with nonliquefied (permanent)
compressed gases or adsorbed gases.

    (a) * * *
    (2) Adsorbed gas. A cylinder filled with an adsorbed gas must be
offered for transportation in conformance with the requirements of
paragraph (d) of this section and Sec.  173.301 of this subpart. In
addition, UN pressure receptacles must meet the requirements in
Sec. Sec.  173.301b, 173.302b, and 173.302c of this subpart, as
applicable, and DOT-specification cylinders must meet the requirements
of Sec. Sec.  173.301a, 173.302a and 173.302d, as applicable, of this
subpart. Where more than one section applies to a cylinder, the most
restrictive requirements must be followed.
* * * * *
0
13. In Sec.  173.302a, revise paragraph (a)(3) to read as follows:

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

    (a) * * *
    (3) DOT 39 cylinders. When the cylinder is filled with a Division
2.1 flammable gas, the internal volume of the cylinder may not exceed
1.25 L (75 in\3\). For chemical under pressure (see Sec.  172.102,
special provision 362 of this subchapter), the internal volume may not
exceed 50 L (3050 in\3\).
* * * * *
0
14. Add Sec.  173.302d to read as follows:

Sec.  173.302d  Additional requirements for the shipment of adsorbed
gases in DOT-specification cylinders.

    (a) General. A cylinder filled with an adsorbed gas must be offered
for transportation in DOT-specification cylinders subject to the
requirements in this section, and Sec. Sec.  173.301 and 173.302 of
this subpart.
    (b) Packaging. (1) DOT-3E1800, DOT-3AA2015, and DOT-3AA2265
cylinders must be used with a capacity between 0.4 and 7.3 liters.
    (2) Each cylinder authorized by this section must remain in
dedicated product service for its entire life.
    (3) The maximum pressure inside each cylinder must be 0 psig at
70[emsp14][deg]F and 30 psig at 140[emsp14][deg]F.
    (4) The contents of the cylinders must be limited in pressure and
volume so that if totally discharged into the overpack cylinder, the
pressure in the overpack cylinder will not exceed \5/4\ of the MAWP at
55 [deg]C (131[emsp14][deg]F).
    (5) The valve wheel of each cylinder must be secured by a strap
that provides tension in the tightening direction. A plug must be
placed in each valve and the cylinder and valve area must be shrink-
wrapped before being placed in the overpack cylinder. A protective
valve cap must be used on all pressure vessels except the DOT-3E1800
cylinder. Valves on the DOT-3E1800 cylinders must be protected in
conformance with Sec.  173.40(d) of this part.
    (6) Prior to each shipment, the leak integrity of the overpack
cylinder must be verified and have a leak rate no greater than 1 x
10-4 standard atmospheric cubic centimeters per second.
    (7) All closures of the overpack cylinder shall have a method to
determine if they have been tampered with during transportation. The
pressure indicating device on the overpack cylinder may be used to
indicate tampering.
    (8) The shipper must instruct the carriers to reject or remove the
overpack cylinder from transportation in the event that the pressure
gauge drops below a pressure designated by the shipper.
    (9) Each overpack cylinder must be labeled for the hazardous
material it contains.
    (10) Adsorbent material. Each cylinder is filled with a monolith
solid microporous sorbent and/or bead-type sorbent onto which the gas
is adsorbed. The gas remains adsorbed during transportation in
essentially a solid state. The system is filled, operated, and
transported at sub-atmospheric pressures and is described as a sub-
atmospheric gas delivery system (SDS). The gas must be removed from the
SDS using the input of external energy, such as a steady vacuum.
    (11) Overpack. (i) Cylinders authorized under this section must be
transported in a non-DOT-specification full-opening, hinged-head or
fully removable head, steel overpack cylinder. The overpack cylinder
must be constructed to Section VIII, Division 1 of the ASME Code (IBR;
see Sec.  171.7 of this subchapter) with a minimum design margin of 4
to 1. The minimum MAWP must be 75 psig. The maximum water capacity must
be 450 L (119 gallons). The overpack cylinder must not be equipped with
a pressure relief device. The cylinders must be securely positioned
within the overpack to prevent excessive movement. The overpack
cylinder must have gaskets, valves and fittings that are compatible

with the hazardous materials they contain. The overpack cylinder must
have a pressure gauge clearly visible from the outside. The pressure
gauge must be recessed into the overpack cylinder or otherwise
protected from damage during transportation. The overpack cylinder must
be pressurized to 3-5 psig with inert gas.
    (ii) Overpack testing. Each overpack cylinder must be visually
inspected in conformance with CGA C-6 (IBR; see Sec.  171.7 of this
subchapter) at least once every five years. In addition, each overpack
must be pressure tested to a minimum test pressure of at least 1.5
times MAWP. The pressure must be maintained for at least 30 seconds.
The cylinder must be examined under test pressure and removed from
service if a leak or defect is found. The retest and inspection must be
performed by a person trained and experienced in the use of the
inspection and testing equipment.
    (iii) Overpack marking. Each overpack cylinder that is successfully
requalified must be durably and legibly marked with the word ``Tested''
followed by the requalification date (month/year). The marking must be
in letters and numbers at least 12 mm (0.5 inches) high. Stamping on
the overpack sidewall is not permitted. The requalification marking may
be placed on any portion of the upper end of the cylinder near the
marking required by the following method, or on a metal plate
permanently secured to the cylinder. The outside of each overpack
cylinder must be plainly and durably marked on any portion of the upper
end with ``OVERPACK CYLINDER'' (in lieu of the ``OVERPACK'' marking
requirement of Sec.  173.25(a)(4) of this part), the proper shipping
name of the hazardous material contained inside the overpack, the name
and address of the consignee or consignor, and the name and address or
registered symbol of the overpack manufacturer.
    (iv) Recordkeeping. The person who tested the overpack or that
person's agent must retain a record of the most recent visual
inspection and pressure test of the overpack until the cylinder is
requalified. The records must be made available to a DOT representative
upon request.
    (12) Sub-atmospheric gas delivery system (SDS) testing. Each
cylinder, except DOT-3E cylinders, must be retested by persons trained
to perform this procedure. DOT-3AA cylinders must be retested and
marked in conformance with the requirements for DOT-3AA cylinders in 49
CFR part 180 or the requirements of a current DOT special permit for
ultrasonic examination.
    (c) Gases. The gases permitted to be transported as adsorbed in
DOT-specification cylinders in conformance with this section are:

----------------------------------------------------------------------------------------------------------------
   Proper shipping name/hazardous     Hazard  class/
        materials description            division          Identification No.                Hazard zone
----------------------------------------------------------------------------------------------------------------
Arsine..............................             2.3  UN 2188.....................  Zone A.
Boron Trifluoride...................             2.3  UN 1008.....................  Zone B.
Hydrogen Selenide, Anhydrous........             2.3  UN 2202.....................  Zone A.
Liquefied Gas, Toxic, Corrosive,                 2.3  UN 3308.....................
 n.o.s. (Arsenic Pentafluoride).
Liquefied Gas, Toxic, Corrosive,                 2.3  UN 3308.....................  Zone B.
 n.o.s. (Germanium Tetrafluoride).
Liquefied Gas, Toxic, Corrosive,                 2.3  UN 3308.....................
 n.o.s. (Phosphorus Trifluoride).
Phosphine...........................             2.3  UN 2199.....................  Zone A.
Silicon Tetrafluoride...............             2.3  UN 1859.....................  Zone B.
----------------------------------------------------------------------------------------------------------------

0
15. In Sec.  173.304a, add paragraph (a)(3) to read as follows:

Sec.  173.304a  Additional requirements for shipment of liquefied
compressed gases in specification cylinders.

    (a) * * *
    (3) The internal volume of a DOT 39 cylinder may not exceed 1.23
liters (nominal 75 in\3\) for a liquefied flammable gas. This cylinder
shall be equipped with a pressure relief device as defined by the
commodity in CGA S-1.1 (IBR; see Sec.  171.7 of this subchapter). If
the commodity is not listed in CGA S-1.1, a CG-7 pressure relief valve
must be used.
* * * * *
0
16. In Sec.  173.306, revise paragraph (g) to read as follows:

Sec.  173.306  Limited quantities of compressed gases.

* * * * *
    (g) Water pump system tank. A water pump system tank charged with
compressed air or limited quantities of nitrogen or helium to not over
40 psig for single trip shipment to an installation site is excepted
from labeling, and the specification packaging requirements of this
subchapter when shipped under the following conditions. In addition,
shipments of these tanks are not subject to subpart F (placarding)
requirements of part 172 of this subchapter, and not subject to parts
174 (except Sec.  174.24) and 177 (except Sec.  177.817) of this
subchapter.
    (1) The tank must be of steel or composite, with heads concave to
pressure, having a rated water capacity not exceeding 120 gallons and
with an outside diameter not exceeding 24 inches. Safety relief devices
are not required.
    (2) The tank must be pneumatically tested to the manufacturer's
specified maximum working pressure. The test pressure must be
permanently marked on the tank.
    (3) The stress at prescribed pressure for steel tanks must not
exceed 20,000 psi (or 25,000 psi for deep-draw steel), concave dome
tanks using the formula:

S = Pd/2t

Where:

S = wall stress in psi:
P = prescribed pressure for the tank of at least three (3) times
charged pressure at 70[emsp14][deg]F or 100 psig, whichever is
greater;
d = inside diameter in inches;
t = minimum wall thickness, in inches.

    (4) For composite tanks, the minimum value of a hydrostatic leak
test, per design, must be at least six (6) times the charge pressure at
70 [deg]F or three (3) times the manufacturer's specified maximum
working pressure, whichever is greater.
    (5) For steel and composite tanks, the burst pressure must be at
least six (6) times the charge pressure at 70 [deg]F or three (3) times
the manufacturer's specified maximum working pressure, whichever is
greater.
    (6) Each tank must be over-packed in a strong outer packaging in
conformance with Sec.  173.301(h) of this part.
    (7) Transportation is limited to motor vehicle, railcar, and
vessel. Transportation by aircraft is not authorized.
* * * * *
0
17. In Sec.  173.309, revise the introductory text to read as follows:

Sec.  173.309  Fire extinguishers.

    This section applies to portable fire extinguishers for manual
handling and operation, fire extinguishers for installation in
aircraft, fire extinguishers for installation as part of a fire
suppression system, and large fire extinguishers. Large fire
extinguishers include fire extinguishers mounted on wheels for manual
handling; fire extinguishing equipment or machinery mounted on wheels
or wheeled platforms or units transported similar to (small) trailers;
and fire extinguishers composed of a non-rollable pressure drum and
equipment, and handled, for example, by forklift or crane when loaded
or unloaded.
* * * * *
0
18. In Sec.  173.312, revise paragraph (b)(1) to read as follows:

Sec.  173.312  Requirements for shipment of MEGCs.

* * * * *
    (b) * * *
    (1) An MEGC being filled with a liquefied compressed gas must have
each cylinder filled separately by weight. Manifolding during filling
is not authorized. The filling density for DOT-specification cylinders
may not exceed the values contained in Sec.  173.304a(a)(2) of this
subpart and for UN pressure receptacles may not exceed the values in
accordance with Sec.  173.304b(b) of this subpart.
* * * * *

PART 178--SPECIFICATIONS FOR PACKAGINGS

0
19. The authority citation for part 178 continues to read as follows:

    Authority: 49 U.S.C. 5101-5128; 49 CFR 1.81 and 1.97.

0
20. In Sec.  178.35, add paragraph (f)(7) to read as follows:

Sec.  178.35  General requirements for specification cylinders.

* * * * *
    (f) * * *
    (7) Tare weight or mass weight, and water capacity marking. DOT-
specification 4B, 4BA, 4BW, and 4E cylinders manufactured after January
1, 2017, must be marked with the tare weight or mass weight.
Additionally, the cylinder must be permanently marked with the water
capacity. The owner of the cylinder at the time of manufacture must
ensure it is marked with the following information, as applicable:
    (i) Tare weight. The tare weight for a cylinder 25 pounds (11.34
kg) or less at the time of manufacture, with a lower tolerance of 3
percent and an upper tolerance of 1 percent; or for a cylinder
exceeding 25 pounds (11.34 kg) at the time of manufacture, with a lower
tolerance of 2 percent and an upper tolerance of 1 percent. The tare
weight marking must be the actual weight of the fully assembled
cylinder, including the valve(s) and other permanently affixed
appurtenances. Removable protective cap(s) or cover(s) must not be
included in the cylinder tare weight, or
    (ii) Mass weight. The mass weight for a cylinder 25 pounds (11.34
kg) or less at the time of manufacture, with a lower tolerance of 3
percent and an upper tolerance of 1 percent; or the mass weight marking
for a cylinder exceeding 25 pounds (11.34 kg) at the time of
manufacture, with a lower tolerance of 2 percent and an upper tolerance
of 1 percent. The mass weight marking must be the actual weight of the
fully assembled cylinder, excluding valve(s) and removable protective
cap(s) or cover(s); and
    (iii) Water capacity. The water capacity for a cylinder 25 pounds
(11.34 kg) water capacity or less, with a tolerance of minus 1 percent
and no upper tolerance; or for a cylinder exceeding 25 pounds (11.34
kg) water capacity, with a tolerance of minus 0.5 percent and upper
tolerance. The marked water capacity of the cylinder must be the
capacity of the cylinder at the time of manufacture.
* * * * *
0
21. In Sec.  178.36, revise paragraph (i) to read as follows:

Sec.  178.36  Specification 3A and 3AX seamless steel cylinders.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The
testing equipment must be calibrated as prescribed in CGA C-1. All
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to a minimum of 5/3 times service
pressure.
    (3) The minimum test pressure must be maintained for at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and previous to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error the test pressure
cannot be maintained the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent, volumetric expansion may not exceed 10 percent of
the total volumetric expansion at test pressure.
* * * * *
0
22. In Sec.  178.37, revise paragraph (i) to read as follows:

Sec.  178.37  Specification 3AA and 3AAX seamless steel cylinders.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The
testing equipment must be calibrated as prescribed in CGA C-1. All
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to a minimum of 5/3 times service
pressure.
    (3) The minimum test pressure must be maintained for at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and previous to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error the test pressure
cannot be maintained the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent, volumetric expansion may not exceed 10 percent of
the total volumetric expansion at test pressure.
* * * * *
0
23. In Sec.  178.38, revise paragraph (i) to read as follows:

Sec.  178.38  Specification 3B seamless steel cylinders.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as
defined in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The
testing equipment must be calibrated as prescribed in CGA Pamphlet C-1.
All testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA Pamphlet C-1.
    (2) Cylinders must be tested as follows:
    (i) Each cylinder to at least two (2) times its service pressure;
or
    (ii) One (1) cylinder out of each lot of 200 or fewer to at least
three (3) times its service pressure.
    (3) When each cylinder is tested to the minimum test pressure, the
minimum test pressure must be maintained at least 30 seconds and
sufficiently longer to

ensure complete expansion. Any internal pressure applied after heat-
treatment and prior to the official test may not exceed 90 percent of
the test pressure. If, due to failure of the test apparatus or operator
error, the test pressure cannot be maintained, the test may be repeated
at a pressure increased by 10 percent or 100 psig, whichever is lower.
    (4) Permanent volumetric expansion may not exceed 10 percent of
total volumetric expansion at test pressure.
    (5) When one (1) cylinder out of each lot of 200 or less is tested
to at least 3 times service pressure, the balance of the lot must be
pressure tested by the water-jacket, direct expansion or proof pressure
test methods as defined in CGA C-1. The testing equipment must be
calibrated as prescribed in CGA C-1. All testing equipment and pressure
indicating devices must be accurate within the parameters defined in
CGA C-1. The cylinders must be subjected to at least 2 times service
pressure and show no defect. Determination of expansion properties is
not required.
* * * * *
0
24. In Sec.  178.39, revise paragraph (i) to read as follows:

Sec.  178.39  Specification 3BN seamless nickel cylinders.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The
testing equipment must be calibrated as prescribed in CGAC-1. All
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to a minimum of at least two (2)
times its service pressure.
    (3) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent volumetric expansion may not exceed 10 percent of
total volumetric expansion at test pressure.
* * * * *
0
25. In Sec.  178.42, revise paragraph (f) to read as follows:

Sec.  178.42  Specification 3E seamless steel cylinders.

* * * * *
    (f) Pressure testing. Cylinders must withstand a pressure test as
follows:
    (1) Lot Testing. One cylinder out of each lot of 500 or fewer must
be subjected to a test pressure of 6,000 psig or higher. The testing
equipment must be calibrated as prescribed in CGA Pamphlet C-1. All
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA Pamphlet C-1
    (2) Pressure Testing. The remaining cylinders of the lot must be
pressure tested by water jacket, direct expansion or proof pressure
method as prescribed in CGA C-1 (IBR; see Sec.  171.7 of this
subchapter). The cylinders must be examined under pressure of at least
3,000 psig and not to exceed 4,500 psig and show no defect. The test
pressure must be maintained for at least 30 seconds and sufficiently
longer to ensure complete examination.
    (3) Burst Testing. (i) The cylinder in paragraph (f)(1) of this
section must burst at a pressure higher than 6,000 psig without
fragmenting or otherwise showing lack of ductility, or must hold a
pressure of 12,000 psig for 30 seconds without bursting. In which case,
it must be subjected to a flattening test without cracking to six (6)
times wall thickness between knife edges, wedge shaped 60-degree angle,
rounded out to a half-inch radius. The inspector's report must be
suitably changed to show results of latter alternate and flattening
test.
    (ii) The cylinders in paragraph (f)(2) tested at a pressure in
excess of 3,600 psig must burst at a pressure higher than 7,500 psig.
* * * * *
0
26. In Sec.  178.44, revise paragraph (i) to read as follows:

Sec.  178.44  Specification 3HT seamless steel cylinders for aircraft
use.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The
testing equipment must be calibrated as prescribed in CGA C-1. All
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to minimum of 5/3 times service
pressure.
    (3) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent volumetric expansion may not exceed 10 percent of
total volumetric expansion at test pressure.
* * * * *
0
27. In Sec.  178.45, revise paragraph (g) to read as follows:

Sec.  178.45  Specification 3T seamless steel cylinder.

* * * * *
    (g) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The
testing equipment must be calibrated as prescribed in CGA C-1. All
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to minimum of 5/3 times service
pressure.
    (3) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent volumetric expansion may not exceed 10 percent of
total volumetric expansion at test pressure.
* * * * *
0
28. In Sec.  178.46, revise paragraph (g) to read as follows:

Sec.  178.46  Specification 3AL seamless aluminum cylinders.

* * * * *
    (g) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The
testing equipment must be calibrated as prescribed in CGA C-1. All
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA C-1.
    (2) The minimum test pressure must be the greater of the following:

    (i) 450 psig regardless of service pressure;
    (ii) Two (2) times the service pressure for cylinders having
service pressure less than 500 psig; or
    (iii) 5/3 times the service pressure for cylinders having a service
pressure of 500 psig or greater.
    (3) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower. If the test apparatus
again fails to maintain the test pressure, the cylinder being tested
must be condemned. Any internal pressure applied to the cylinder before
any official test may not exceed 90 percent of the test pressure.
    (4) Permanent volumetric expansion may not exceed 10 percent of
total volumetric expansion at test pressure.
* * * * *
0
29. In Sec.  178.47, revise paragraph (j) to read as follows:

Sec.  178.47  Specification 4DS welded stainless steel cylinders for
aircraft use.

* * * * *
    (j) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The
testing equipment must be calibrated as prescribed in CGA C-1. All
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to a minimum of at least two (2)
times its service pressure.
    (3) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent volumetric expansion may not exceed 10 percent of the
total volumetric expansion at test pressure.
    (5) Cause for condemnation. Following the pressure test, the
cylinder must be inspected. A cylinder with wall thickness less than
that required by paragraph (f) of this section must be condemned.
Bulges and cracks are cause for condemnation. Welded joint defects
exceeding requirements of paragraph (k) of this section are cause for
condemnation.
* * * * *
0
30. Revise Sec.  178.50 to read as follows:

Sec.  178.50  Specification 4B welded or brazed steel cylinders.

    (a) Type, size, pressure, and application. A DOT 4B is a welded or
brazed steel cylinder with longitudinal seams that are forged lap-
welded or brazed and with water capacity (nominal) not over 1,000
pounds and a service pressure of at least 150 but not over 500 psig.
Cylinders closed in by spinning process are not authorized.
    (b) Steel. Open-hearth, electric or basic oxygen process steel of
uniform quality must be used. Content percent may not exceed the
following: carbon, 0.25; phosphorus, 0.045; sulphur, 0.050. The
cylinder manufacturer must maintain a record of intentionally added
alloying elements.
    (c) Identification of material. Pressure-retaining materials must
be identified by any suitable method that does not compromise the
integrity of the cylinder. Plates and billets for hotdrawn cylinders
must be marked with the heat number.
    (d) Manufacture. Cylinders must be manufactured using equipment and
processes adequate to ensure that each cylinder produced conforms to
the requirements of this subpart. No defect is permitted that is likely
to weaken the finished cylinder appreciably. A reasonably smooth and
uniform surface finish is required. Exposed bottom welds on cylinders
over 18 inches long must be protected by footrings. Welding procedures
and operators must be qualified in conformance with CGA C-3 (IBR, see
Sec.  171.7 of this subchapter). Seams must be made as follows:
    (1) Brazing materials. Brazing materials must be by copper brazing,
by copper alloy brazing, or by silver alloy brazing. Copper alloy
composition must be: Copper, 95 percent minimum; Silicon, 1.5 percent
to 3.85 percent; Manganese, 0.25 percent to 1.10 percent.
    (2) Brazed circumferential seams. Heads attached by brazing must
have a driving fit with the shell, unless the shell is crimped,
swedged, or curled over the skirt or flange of the head, and be
thoroughly brazed until complete penetration by the brazing material of
the brazed joint is secured. Depth of brazing of the joint must be at
least four (4) times the minimum thickness of shell metal.
    (3) Welded circumferential seams. Circumferential seams are
permitted by the welding process.
    (4) Longitudinal seams in shells. Longitudinal seams must be a
forged lap joint design. When brazed, the plate edge must be lapped at
least eight (8) times the thickness of the plate, laps being held in
position, substantially metal to metal, by riveting or electric spot-
welding; brazing must be done by using a suitable flux and by placing
brazing material on one side of seam and applying heat until this
material shows uniformly along the seam of the other side.
    (e) Welding or brazing. Only the attachment of neckrings,
footrings, handles, bosses, pads, and valve protection rings to the
tops and bottoms of cylinders by welding or brazing is authorized.
Attachments and the portion of the cylinder to which they are attached
must be made of weldable steel, the carbon content of which may not
exceed 0.25 percent except in the case of 4130X steel, which may be
used with proper welding procedure.
    (f) Wall thickness. The wall thickness of the cylinder must comply
with the following requirements:
    (1) For cylinders with outside diameters over 6 inches, the minimum
wall thickness must be 0.090 inch. In any case, the minimum wall
thickness must be such that calculated wall stress at minimum test
pressure (paragraph (i)(4) of this section) may not exceed the
following values:
    (i) 24,000 psi for cylinders without longitudinal seam.
    (ii) 22,800 psig for cylinders having copper brazed or silver alloy
brazed longitudinal seam.
    (iii) 18,000 psi for cylinders having forged lapped welded
longitudinal seam.
    (2) Calculation must be made by the formula:

S = [P(1.3D\2\ + 0.4d\2\)]/(D\2\ - d\2\)

Where:

S = wall stress in psi;
P = minimum test pressure prescribed for water jacket test or 450
psig whichever is the greater;
D = outside diameter in inches;
d = inside diameter in inches.

    (g) Heat treatment. Cylinder heads, bodies or the completed
cylinder, formed by drawing or pressing, must be uniformly and properly
heat treated by an applicable method shown in table 1 of appendix A of
this part before tests.
    (h) Opening in cylinders. Openings in cylinders must comply with
the following:

    (1) Any opening must be placed on other than a cylindrical surface.
    (2) Each opening in a spherical type of cylinder must be provided
with a fitting, boss, or pad of weldable steel securely attached to the
cylinder by fusion welding.
    (3) Each opening in a cylindrical type cylinder, except those for
pressure relief devices, must be provided with a fitting, boss, or pad,
securely attached to container by brazing or by welding.
    (4) If threads are used, they must comply with the following:
    (i) Threads must be clean cut, even without checks, and tapped to
gauge.
    (ii) Taper threads must be of a length not less than as specified
for American Standard taper pipe threads.
    (iii) Straight threads, must have at least four (4) engaged
threads, must have tight fit and a calculated shear strength at least
ten (10) times the test pressure of the cylinder; gaskets are required
for straight threads and must be of sufficient quality to prevent
leakage.
    (iv) A brass fitting may be brazed to the steel boss or flange on
cylinders used as component parts of handheld fire extinguishers.
    (5) The closure of a fitting, boss, or pad must be adequate to
prevent leakage.
    (i) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) Lot testing. (i) At least one (1) cylinder randomly selected
out of each lot of 200 or fewer must be tested by the water jacket or
direct expansion method as prescribed in CGA C-1 (IBR; see Sec.  171.7
of this subchapter). The testing equipment must be calibrated as
prescribed in CGA C-1. All testing equipment and pressure indicating
devices must be accurate within the parameters defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of 2 times service
pressure.
    (iii) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (iv) Permanent volumetric expansion may not exceed 10 percent of
the total volumetric expansion at test pressure.
    (2) Pressure testing. (i) The remaining cylinders in the lot must
be tested by the water-jacket, direct expansion or proof pressure test
methods as prescribed in CGA C-1. The minimum test pressure must be
maintained for a specific timeframe as prescribed and the testing
equipment must be calibrated as prescribed in CGA C-1. Further, all
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA C-1. Determination of expansion
properties is not required.
    (ii) Each cylinder must be tested to a minimum of at least two (2)
times service pressure and show no defect.
    (j) Mechanical test. A mechanical test must be conducted to
determine yield strength, tensile strength, elongation as a percentage,
and reduction of area of material as a percentage as follows:
    (1) Testing is required on two (2) specimens removed from one (1)
cylinder, or part thereof, heat-treated as required, as illustrated in
appendix A to subpart C of this part. For lots of 30 or fewer,
mechanical tests are authorized to be made on a ring at least 8 inches
long removed from each cylinder and subjected to the same heat of
material taken as the finished cylinder.
    (2) Specimens must comply with the following:
    (i) When a cylinder wall is \3/16\ inch thick or less, one the
following gauge lengths is authorized: A gauge length of 8 inches with
a width not over 1\1/2\ inches, a gauge length of 2 inches with a width
not over 1\1/2\ inches, or a gauge length at least twenty-four (24)
times the thickness with a width not over six (6) times the thickness.
    (ii) The specimen, exclusive of grip ends, may not be flattened.
Grip ends may be flattened to within one inch of each end of the
reduced section.
    (iii) When the size of a cylinder does not permit securing straight
specimens, the specimens may be taken in any location or direction and
may be straightened or flattened cold, by pressure only, not by blows.
When specimens are taken and prepared using this method, the
inspector's report must show detailed information regarding such
specimens in connection with the record of mechanical tests.
    (iv) Heating of a specimen for any purpose is not authorized.
    (3) The yield strength in tension must be the stress corresponding
to a permanent strain of 0.2 percent of the gauge length. The following
conditions apply:
    (i) The yield strength must be determined by either the ``offset''
method or the ``extension under load'' method as prescribed in ASTM E 8
(IBR, see Sec.  171.7 of this subchapter).
    (ii) In using the ``extension under load'' method, the total strain
(or ``extension under load'') corresponding to the stress at which the
0.2 percent permanent strain occurs may be determined with sufficient
accuracy by calculating the elastic extension of the gauge length under
appropriate load and adding thereto 0.2 percent of the gauge length.
Elastic extension calculations must be based on an elastic modulus of
30,000,000. In the event of controversy, the entire stress-strain
diagram must be plotted and the yield strength determined from the 0.2
percent offset.
    (iii) For the purpose of strain measurement, the initial strain
reference must be set while the specimen is under a stress of 12,000
psi, and strain indicator reading must be set at the calculated
corresponding strain.
    (iv) Cross-head speed of the testing machine may not exceed 18 inch
per minute during yield strength determination.
    (v) The yield strength must not exceed 73 percent of the tensile
strength.
    (k) Elongation. Mechanical test specimens must show at least a 20
percent elongation. However, elongation percentages may be reduced
numerically by one (1) percentage for each 7,500 psi increase of
tensile strength above 50,000 psi. The tensile strength may be
incrementally increased by a maximum total of 30,000 psi.
    (l) Flattening test. (1) Cylinders. After pressure testing, a
flattening test must be performed on one cylinder taken at random out
of each lot of 200 or fewer by placing the cylinder between wedge-
shaped knife edges having a 60 degree included angle, rounded to a
half-inch radius. The longitudinal axis of the cylinder must be at a
90-deqree angle to knife edges during the test. For lots of 30 or
fewer, flattening tests are authorized to be performed on a ring of at
least 8 inches long removed from each cylinder and subjected to same
heat of material taken as the finished cylinder.
    (2) Pipes. When cylinders are constructed of lap welded pipe, an
additional flattening test is required, without evidence of cracking,
up to six (6) times the wall thickness. In such case, the rings (crop
ends) removed from each end of the pipe, must be tested with the weld
45[emsp14][deg]F or less from the point of greatest stress.
    (m) Acceptable results for flattening tests. There must be no
evidence of cracking of the sample when it is flattened between flat
plates to no more than six (6) times the wall thickness. If this test
fails, one additional sample from the same lot may be taken. If this
second sample fails, the entire lot must be condemned.
    (n) Condemned cylinders. (1) Unless otherwise stated in this
section, if a

sample cylinder or specimen taken from a lot of cylinders fails the
prescribed test, then two additional specimens must be selected from
the same lot and subjected to the prescribed test. If either of these
fails the test, then the entire lot must be condemned.
    (2) Reheat treatment of a condemned cylinder. Reheat treatment is
authorized for a condemned cylinder in accordance with this paragraph.
After reheat treatment, a cylinder must pass all prescribed tests in
this section to be considered acceptable. Repair of brazed seams by
brazing and welded seams by welding is authorized. For cylinders with
an outside diameter of less than or equal to six (6) inches, welded
seam repairs greater than one (1) inch in length shall require reheat
treatment of the cylinder. For cylinders greater than an outside
diameter of 6 inches, welded seam repairs greater than three (3) inches
in length shall require reheat treatment.
    (o) Markings. (1) Markings must be as required as in Sec.  178.35
of this subpart and in addition must be stamped plainly and permanently
in any of the following locations on the cylinder:
    (i) On shoulders and top heads whose wall thickness is not less
than 0.087-inch thick;
    (ii) On side wall adjacent to top head for side walls which are not
less than 0.090 inch thick;
    (iii) On a cylindrical portion of the shell that extends beyond the
recessed bottom of the cylinder, constituting an integral and non-
pressure part of the cylinder;
    (iv) On a metal plate attached to the top of the cylinder or
permanent part thereof; sufficient space must be left on the plate to
provide for stamping at least six retest dates; the plate must be at
least \1/16\-inch thick and must be attached by welding, or by brazing.
The brazing rod must melt at a temperature of 1100[emsp14][deg]F.
Welding or brazing must be along all the edges of the plate;
    (v) On the neck, neckring, valve boss, valve protection sleeve, or
similar part permanently attached to the top of the cylinder; or
    (vi) On the footring permanently attached to the cylinder, provided
the water capacity of the cylinder does not exceed 30 pounds.
    (2) Embossing the cylinder head or sidewall is not permitted.
0
31. Revise Sec.  178.51 to read as follows:

Sec.  178.51  Specification 4BA welded or brazed steel cylinders.

    (a) Type, size, pressure, and application. A DOT 4BA cylinder is a
cylinder, either spherical or cylindrical design, with a water capacity
of 1,000 pounds or less and a service pressure range of 225 to 500
psig. Closures made by the spinning process are not authorized.
    (1) Spherical type cylinder designs are permitted to have only one
circumferentially welded seam.
    (2) Cylindrical type cylinder designs must be of circumferentially
welded or brazed construction; longitudinally brazed or silver-soldered
seams are also permitted.
    (b) Steel. The steel used in the construction of the cylinder must
be as specified in table 1 of appendix A to this part. The cylinder
manufacturer must maintain a record of intentionally added alloying
elements.
    (c) Identification of material. Pressure-retaining material must be
identified by any suitable method that does not compromise the
integrity of the cylinder. Plates and billets for hotdrawn cylinders
must be marked with the heat number.
    (d) Manufacture. Cylinders must be manufactured using equipment and
processes adequate to ensure that each cylinder produced conforms to
the requirements of this subpart. No defect is permitted that is likely
to appreciably weaken the finished cylinder. A reasonably smooth and
uniform surface finish is required. Exposed bottom welds on cylinders
over 18 inches long must be protected by footrings.
    (1) Seams must be made as follows:
    (i) Minimum thickness of heads and bottoms must be not less than 90
percent of the required thickness of the side wall.
    (ii) Circumferential seams must be made by welding or by brazing.
Heads attached by brazing must have a driving fit with the shell unless
the shell is crimped, swedged or curled over the skirt or flange of the
head and must be thoroughly brazed until complete penetration by the
brazing material of the brazed joint is secured. Depth of brazing from
end of the shell must be at least four (4) times the thickness of shell
metal.
    (iii) Longitudinal seams in shells must be made by copper brazing,
copper alloy brazing, or by silver alloy brazing. Copper alloy
composition must be: Copper 95 percent minimum, Silicon 1.5 percent to
3.85 percent, Manganese 0.25 percent to 1.10 percent. The melting point
of the silver alloy brazing material must be in excess of
1,000[emsp14][deg]F. The plate edge must be lapped at least eight times
the thickness of plate, laps being held in position, substantially
metal to metal, by riveting or by electric spot-welding. Brazing must
be done by using a suitable flux and by placing brazing material on one
side of seam and applying heat until this material shows uniformly
along the seam of the other side. Strength of longitudinal seam: Copper
brazed longitudinal seam must have strength at least 3/2 times the
strength of the steel wall.
    (2) Welding procedures and operators must be qualified in
conformance with CGA C-3 (IBR, see Sec.  171.7 of this subchapter).
    (e) Welding or brazing. Welding or brazing of any attachment or
opening to the heads of cylinders is permitted provided the carbon
content of the steel does not exceed 0.25 percent except in the case of
4130 x steel, which may be used with proper welding procedure.
    (f) Wall thickness. The minimum wall thickness of the cylinder must
meet the following conditions:
    (1) For any cylinder with an outside diameter of greater than 6
inches, the minimum wall thickness is 0.078 inch. In any case, the
minimum wall thickness must be such that the calculated wall stress at
the minimum test pressure may not exceed the lesser value of any of the
following:
    (i) The value shown in table 1 of appendix A to this part, for the
particular material under consideration;
    (ii) One-half of the minimum tensile strength of the material
determined as required in paragraph (j) of this section;
    (iii) 35,000 psi; or
    (iv) Further provided that wall stress for cylinders having copper
brazed longitudinal seams may not exceed 95 percent of any of the above
values. Measured wall thickness may not include galvanizing or other
protective coating.
    (2) Cylinders that are cylindrical in shape must have the wall
stress calculated by the formula:

S = [P(1.3D\2\ + 0.4d\2\)]/(D\2\ - d\2\)

Where:

S = wall stress in psi;
P = minimum test pressure prescribed for water jacket test;
D = outside diameter in inches;
d = inside diameter in inches.

    (3) Cylinders that are spherical in shape must have the wall stress
calculated by the formula:

S = PD/4tE

Where:

S = wall stress in psi;
P = minimum test pressure prescribed for water jacket test;
D = outside diameter in inches;
t = minimum wall thickness in inches;
E = 0.85 (provides 85 percent weld efficiency factor which must be
applied in the girth weld area and heat affected zones which zone
must extend a distance of 6 times wall thickness from center line of
weld);
E = 1.0 (for all other areas).

    (4) For a cylinder with a wall thickness less than 0.100 inch, the
ratio of tangential length to outside diameter may not exceed 4.1.
    (g) Heat treatment. Cylinders must be heat treated in accordance
with the following requirements:
    (1) Each cylinder must be uniformly and properly heat treated prior
to test by the applicable method shown in table 1 of appendix A to this
part. Heat treatment must be accomplished after all forming and welding
operations, except that when brazed joints are used, heat treatment
must follow any forming and welding operations, but may be done before,
during or after the brazing operations [see Sec.  178.51(m) for weld
repairs].
    (2) Heat treatment is not required after the welding or brazing of
weldable low carbon parts to attachments of similar material which have
been previously welded or brazed to the top or bottom of cylinders and
properly heat treated, provided such subsequent welding or brazing does
not produce a temperature in excess of 400[emsp14][deg]F in any part of
the top or bottom material.
    (h) Openings in cylinders. Openings in cylinders must comply with
the following requirements:
    (1) Any opening must be placed on other than a cylindrical surface.
    (2) Each opening in a spherical type cylinder must be provided with
a fitting, boss, or pad of weldable steel securely attached to the
container by fusion welding.
    (3) Each opening in a cylindrical type cylinder must be provided
with a fitting, boss, or pad, securely attached to container by brazing
or by welding.
    (4) If threads are used, they must comply with the following:
    (i) Threads must be clean-cut, even, without checks and tapped to
gauge.
    (ii) Taper threads must be of a length not less than that specified
for American Standard taper pipe threads.
    (iii) Straight threads, having at least 4 engaged threads, must
have a tight fit and a calculated shear strength of at least 10 times
the test pressure of the cylinder. Gaskets, adequate to prevent
leakage, are required.
    (i) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) Lot testing. (i) At least one (1) cylinder randomly selected
out of each lot of 200 or fewer must be tested by water jacket or
direct expansion method as prescribed in CGA C-1 (IBR, see Sec.  171.7
of this subchapter). The testing equipment must be calibrated as
prescribed in CGA C-1. All testing equipment and pressure indicating
devices must be accurate within the parameters defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of two (2) times
service pressure.
    (iii) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (iv) Permanent volumetric expansion may not exceed 10 percent of
the total volumetric expansion at test pressure.
    (2) Pressure testing. (i) The remaining cylinders in the lot must
be tested by the water-jacket, direct expansion or proof pressure test
methods as prescribed in CGA C-1. The minimum test pressure must be
maintained for a specific timeframe and the testing equipment must be
calibrated as prescribed in CGA C-1. Further, all testing equipment and
pressure indicating devices must be accurate within the parameters
defined in CGA C-1. Determination of expansion properties is not
required.
    (ii) Each cylinder must be tested to a minimum of two (2) times
service pressure and show no defect.
    (j) Mechanical test. (1) A mechanical test must be conducted to
determine yield strength, tensile strength, elongation as a percentage,
and reduction of area of material as a percentage, as follows:
    (i) Cylinders. Testing is required on two (2) specimens removed
from one cylinder or part thereof taken at random out of each lot of
200 or fewer. Samples must be removed as illustrated in appendix A to
subpart C of this part.
    (ii) Spheres. Testing is required on two (2) specimens removed from
the sphere or flat representative sample plates of the same heat of
material taken at random from the steel used to produce the spheres.
Samples (including plates) must be taken from each lot of 200 or fewer.
The flat steel from which two specimens are to be removed must receive
the same heat of material taken as the as the spheres themselves.
Samples must be removed as illustrated in appendix A to subpart C of
this part.
    (2) Specimens must comply with the following:
    (i) When a cylinder wall is \3/16\ inch thick or less, one the
following gauge lengths is authorized: A gauge length of 8 inches with
a width not over 1\1/2\ inches, a gauge length of 2 inches with a width
not over 1\1/2\ inches, or a gauge length at least twenty-four (24)
times the thickness with a width not over six (6) times the thickness.
    (ii) The specimen, exclusive of grip ends, may not be flattened.
Grip ends may be flattened to within one inch of each end of the
reduced section.
    (iii) When size of the cylinder does not permit securing straight
specimens, the specimens may be taken in any location or direction and
may be straightened or flattened cold, by pressure only, not by blows.
When specimens are so taken and prepared, the inspector's report must
show in connection with record of physical tests detailed information
in regard to such specimens.
    (iv) Heating of a specimen for any purpose is not authorized.
    (3) The yield strength in tension must be the stress corresponding
to a permanent strain of 0.2 percent of the gauge length. The following
conditions apply:
    (i) The yield strength must be determined by either the ``offset''
method or the ``extension under load'' method as prescribed in ASTM E 8
(IBR, see Sec.  171.7 of this subchapter).
    (ii) In using the ``extension under load'' method, the total strain
(or ``extension under load''), corresponding to the stress at which the
0.2 percent permanent strain occurs may be determined with sufficient
accuracy by calculating the elastic extension of the gauge length under
appropriate load and adding thereto 0.2 percent of the gauge length.
Elastic extension calculations must be based on an elastic modulus of
30,000,000. In the event of controversy, the entire stress-strain
diagram must be plotted and the yield strength determined from the 0.2
percent offset.
    (iii) For the purpose of strain measurement, the initial strain
reference must be set while the specimen is under a stress of 12,000
psi, and the strain indicator reading must be set at the calculated
corresponding strain.
    (k) Elongation. Mechanical test specimens must show at least a 40
percent elongation for a 2-inch gauge length or at least 20 percent in
other cases. However, elongation percentages may be reduced numerically
by 2 percent for 2-inch specimens, and by 1 percent in other cases, for
each 7,500 psi increase of tensile strength above 50,000 psi. The
tensile strength may be incrementally increased by a maximum total of
30,000 psi.
    (l) Tests of welds. Except for brazed seams, welds must be tested
as follows:
    (1) Tensile test. A specimen must be removed from one cylinder of
each lot

of 200 or fewer, or welded test plate. The welded test plate must be of
one of the heats in the lot of 200 or fewer which it represents, in the
same condition and approximately the same thickness as the cylinder
wall except that in no case must it be of a lesser thickness than that
required for a quarter size Charpy impact specimen. The weld must be
made by the same procedures and subjected to the same heat of material
taken as the major weld on the cylinder. The specimen must be taken
from across the major seam and must be prepared and tested in
conformance with and must meet the requirements of CGA C-3 (IBR, see
Sec.  171.7 of this subchapter). Should this specimen fail to meet the
requirements, one additional specimen must be taken from two additional
cylinders or welded test plates from the same lot and tested. If any of
these latter two specimens fail to meet the requirements, the entire
lot represented must be condemned.
    (2) Guided bend test. A root bend test specimen must be removed
from the cylinder or welded test plate, used for the tensile test
specified in paragraph (l)(1) of this section. The specimen must be
taken from across the circumferential seam and must be prepared and
tested in conformance with and must meet the requirements of CGA C-3.
Should this specimen fail to meet the requirements, one additional
specimen must be taken from two additional cylinders or welded test
plates from the same lot and tested. If any of these latter two
specimens fail to meet the requirements, the entire lot represented
must be condemned.
    (3) Alternate guided-bend test. This test may be used and must be
as required by CGA C-3. The specimen must be bent until the elongation
at the outer surface, adjacent to the root of the weld, between the
lightly scribed gage lines a to b, must be at least 20 percent, except
that this percentage may be reduced for steels having a tensile
strength in excess of 50,000 psig, as provided in paragraph (k) of this
section. Should the specimen fail to meet the requirements, one
additional specimen must be taken from two additional cylinders or
welded test plates from the same lot and tested. If any of these latter
two specimens fail to meet the requirements, the entire lot represented
must be condemned.
    (m) Condemned cylinders.
    (1) Unless otherwise stated in this section, if a sample cylinder
or specimen taken from a lot of cylinders fails the prescribed test,
then two additional specimens must be selected from the same lot and
subjected to the prescribed test. If either of these additional
specimens fails the test, then the entire lot must be condemned.
    (2) Reheat treatment of a condemned cylinder. Reheat treatment is
authorized for a condemned cylinder in accordance with this paragraph.
After reheat, a cylinder must pass all prescribed tests in this section
to be acceptable. Repair of brazed seams by brazing and welded seams by
welding is considered authorized. For cylinders with an outside
diameter of less than or equal to six (6) inches, welded seam repairs
greater than one (1) inch in length shall require reheat treatment of
the cylinder. For cylinders greater than an outside diameter of six (6)
inches, welded seam repairs greater than three (3) inches in length
shall require reheat treatment.
    (n) Markings. (1) Markings must be as required in Sec.  178.35 of
this subpart and in addition must be stamped plainly and permanently in
one of the following locations on the cylinder:
    (i) On shoulders and top heads whose wall thickness is not less
than 0.087 inch thick;
    (ii) On side wall adjacent to top head for side walls not less than
0.090 inch thick;
    (iii) On a cylindrical portion of the shell that extends beyond the
recessed bottom of the cylinder constituting an integral and non-
pressure part of the cylinder;
    (iv) On a plate attached to the top of the cylinder or permanent
part thereof; sufficient space must be left on the plate to provide for
stamping at least six retest dates; the plate must be at least \1/16\-
inch thick and must be attached by welding, or by brazing at a
temperature of at least 1100 [deg]F, throughout all edges of the plate;
    (v) On the neck, neckring, valve boss, valve protection sleeve, or
similar part permanently attached to the top of the cylinder; or
    (vi) On the footring permanently attached to the cylinder, provided
the water capacity of the cylinder does not exceed 30 pounds.
    (2) Embossing the cylinder head or side is not permitted.
0
32. In Sec.  178.53, revise paragraph (h) to read as follows:

Sec.  178.53  Specification 4D welded steel cylinders for aircraft use.

* * * * *
    (h) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) Lot Testing. (i) At least one cylinder selected at random out
of each lot of 200 or fewer must be tested by water-jacket or direct
expansion as prescribed in CGA C-1 (IBR; see Sec.  171.7 of this
subchapter). The testing equipment must be calibrated as prescribed in
CGA C-1. All testing equipment and pressure indicating devices must be
accurate within the parameters defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of three (3) times
service pressure.
    (iii) The minimum test pressure must be maintained be maintained at
least 30 seconds and sufficiently longer to ensure complete expansion.
Any internal pressure applied after heat-treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (iv) Permanent volumetric expansion may not exceed 10 percent of
the total volumetric expansion at test pressure.
    (2) Pressure testing. (i) The remaining cylinders in each lot must
be tested by the water-jacket, direct expansion or proof pressure test
methods as prescribed in CGA C-1. The minimum test pressure must be
maintained for a specific timeframe, and the testing equipment must be
calibrated as prescribed in CGA C-1. Further, all testing equipment and
pressure indicating devices must be accurate within the parameters
defined in CGA C-1. Determination of expansion properties is not
required.
    (ii) Each cylinder must be tested to a minimum of two (2) times
service pressure and show no defect.
* * * * *
0
33. In Sec.  178.55, revise paragraph (i) to read as follows:

Sec.  178.55  Specification 4B240ET welded or brazed cylinders.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) Lot Testing. (i) At least one (1) cylinder selected at random
out of each lot of 200 or fewer must be tested by water-jacket or
direct expansion method as prescribed in CGA C-1 (IBR; see Sec.  171.7
of this subchapter). The testing equipment must be calibrated as
prescribed in CGA C-1. All testing equipment and pressure indicating
devices must be accurate within the parameters defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of two (2) times
service pressure.
    (iii) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure

applied after heat-treatment and prior to the official test may not
exceed 90 percent of the test pressure. If, due to failure of the test
apparatus or operator error, the test pressure cannot be maintained,
the test may be repeated at a pressure increased by 10 percent or 100
psig, whichever is lower.
    (iv) Permanent volumetric expansion may not exceed 10 percent of
the total volumetric expansion at test pressure.
    (2) Pressure testing. (i) The remaining cylinders in each lot must
be tested by the water-jacket, direct expansion or proof pressure test
methods as prescribed in CGA C-1. The minimum test pressure must be
maintained for a specific timeframe, and the testing equipment must be
calibrated as prescribed in CGA C-1. All testing equipment and pressure
indicating devices must be accurate within the parameters defined in
CGA C-1. Determination of expansion properties is not required.
    (ii) Each cylinder must be tested to a minimum of two (2) times
service pressure and show no defect.
    (3) Burst testing. (i) For purposes of burst testing, each 1,000
cylinders or fewer successively produced each day constitutes a lot.
All cylinders of a lot must be of identical size, construction heat
treatment, finish, and quality.
    (ii) One cylinder must be selected from each lot and be
hydrostatically pressure tested to destruction. If this cylinder bursts
below five (5) times the service pressure, then two additional
cylinders from the same lot as the previously tested cylinder must be
selected and subjected to this test. If either of these cylinders fails
by bursting below five (5) times the service pressure then the entire
lot must be condemned.
* * * * *
0
34. In Sec.  178.56, revise paragraph (i) to read as follows:

Sec.  178.56  Specification 4AA480 welded steel cylinders.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) Lot testing. (i) At least one (1) cylinder selected at random
out of each lot of 200 or fewer must be tested by water-jacket or
direct expansion method as prescribed in CGA C-1 (IBR; see Sec.  171.7
of this subchapter). The testing equipment must be calibrated as
prescribed in CGA C-1. All testing equipment and pressure indicating
devices must be accurate within the parameters defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of two (2) times
service pressure.
    (iii) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (iv) Permanent volumetric expansion may not exceed 10 percent of
the total volumetric expansion at test pressure.
    (v) If a selected cylinder fails, then two (2) additional specimens
must be selected at random from the same lot and subjected to the
prescribed testing. If either of these fails the test, then each
cylinder in that lot must be tested as prescribed in paragraph (i)(l)
of this section.
    (2) Pressure testing. (i) The remaining cylinders in each lot must
be tested by the water-jacket, direct expansion or proof pressure test
methods as prescribed in CGA C-1. The minimum test pressure must be
maintained for a specific timeframe, and the testing equipment must be
calibrated as prescribed in CGA C-1. Further, all testing equipment and
pressure indicating devices must be accurate within the parameters
defined in CGA C-1. Determination of expansion properties is not
required.
    (ii) Each cylinder must be tested to a minimum of two (2) times
service pressure and show no defect. A cylinder showing a defect must
be condemned unless it may be requalified under paragraph (m) of this
section.
* * * * *
0
35. In Sec.  178.57, revise paragraph (i) to read as follows:

Sec.  178.57  Specification 4L welded insulated cylinders.

* * * * *
    (i) Pressure testing. Each cylinder, before insulating and
jacketing, must successfully withstand a pressure test as follows:
    (1) The cylinder must be tested by water-jacket, direct expansion,
or proof pressure test methods as prescribed in CGA C-1 (IBR; see Sec.
171.7 of this subchapter). The testing equipment must be calibrated as
prescribed in CGA C-1. All testing equipment and pressure indicating
devices must be accurate within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to a minimum of two (2) times
service pressure.
    (3) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (4) There must be no evidence of leakage, visible distortion or
other defect.
* * * * *
0
36. In Sec.  178.58, revise paragraph (i) to read as follows:

Sec.  178.58  Specification 4DA welded steel cylinders for aircraft
use.

* * * * *
    (i) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) The test must be by water-jacket or direct expansion method as
prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The
testing equipment must be calibrated as prescribed in CGA C-1. All
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA C-1.
    (2) Each cylinder must be tested to a minimum of two (2) times
service pressure.
    (3) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (4) Permanent volumetric expansion may not exceed 10 percent of the
total volumetric expansion at test pressure.
* * * * *
0
37. In Sec.  178.59, revise paragraph (h) to read as follows:

Sec.  178.59  Specification 8 steel cylinders with porous fillings for
acetylene.

* * * * *
    (h) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) Lot testing. (i) At least one (1) cylinder selected at random
out of each lot of 200 or fewer must be tested by water-jacket or
direct expansion method

as prescribed in CGA C-1 (IBR; see Sec.  171.7 of this subchapter). The
testing equipment must be calibrated as prescribed in CGA C-1. All
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of 750 psig.
    (iii) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (iv) Permanent volumetric expansion may not exceed 10 percent of
the total volumetric expansion at test pressure.
    (v) If the tested cylinder fails, each cylinder remaining in the
lot may be tested in lieu of paragraph (h)(2) of this section by the
water-jacket or direct expansion method as prescribed in CGA C-1. Those
passing are acceptable.
    (2) Pressure testing. (i) The remaining cylinders in each lot must
be pressure tested by the water-jacket, direct expansion or proof
pressure test methods as prescribed in CGA C-1. The minimum test
pressure must be maintained for a specific timeframe, and the testing
equipment must be calibrated as prescribed in CGA C-1. Further, all
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA C-1. Determination of expansion
properties is not required.
    (ii) Each cylinder must be tested between 500 and 600 psig and show
no defect.
* * * * *
0
38. In Sec.  178.60, revise paragraph (j) to read as follows:

Sec.  178.60  Specification 8AL steel cylinders with porous fillings
for acetylene.

* * * * *
    (j) Pressure testing. Each cylinder must successfully withstand a
pressure test as follows:
    (1) Lot Testing. (i) At least one (1) cylinder selected at random
out of each lot of 200 or less must be tested by water-jacket or direct
expansion method as prescribed in CGA C-1 (IBR; see Sec.  171.7 of this
subchapter). The testing equipment must be calibrated as prescribed in
CGA C-1. All testing equipment and pressure indicating devices must be
accurate within the parameters defined in CGA C-1.
    (ii) Each cylinder must be tested to a minimum of 750 psig.
    (iii) The minimum test pressure must be maintained at least 30
seconds and sufficiently longer to ensure complete expansion. Any
internal pressure applied after heat-treatment and prior to the
official test may not exceed 90 percent of the test pressure. If, due
to failure of the test apparatus or operator error, the test pressure
cannot be maintained, the test may be repeated at a pressure increased
by 10 percent or 100 psig, whichever is lower.
    (iv) Permanent volumetric expansion may not exceed 10 percent of
the total volumetric expansion at test pressure.
    (v) If the tested cylinder fails, each remaining cylinder in the
lot may be tested in lieu of paragraph (j)(2) of this section by the
water-jacket or direct expansion method as prescribed in CGA C-1. Those
passing are acceptable.
    (2) Pressure testing. (i) The remaining cylinders in each lot must
be pressure tested by the water-jacket, direct expansion or proof
pressure test methods as prescribed in CGA C-1. The minimum test
pressure must be maintained for a specific timeframe, and the testing
equipment must be calibrated as prescribed in CGA C-1. Further, all
testing equipment and pressure indicating devices must be accurate
within the parameters defined in CGA C-1. Determination of expansion
properties is not required.
    (ii) Each cylinder must be tested between 500 and 600 psig and show
no defect.
* * * * *
0
39. Revise Sec.  178.61 to read as follows:

Sec.  178.61  Specification 4BW welded steel cylinders with electric-
arc welded seam.

    (a) Type, size, pressure, and application. A DOT 4BW cylinder has a
spherical or cylindrical design, a water capacity of 1,000 pounds or
less, and a service pressure range of 225 to 500 psig. Closures made by
the spinning process are not authorized.
    (1) Spherical designs are permitted to have only one
circumferentially electric-arc welded seam.
    (2) Cylindrical designs must be of circumferentially welded