Hazardous Materials Regulations: Aluminum Cylinders Manufactured of Aluminum Alloy 6351-T6 Used in SCUBA, SCBA, and Oxygen Service-- Revised Requalification and Use Criteria

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

[Federal Register: September 10, 2003 (Volume 68, Number 175)]
[Proposed Rules]
[Page 53314-53320]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr10se03-17]

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DEPARTMENT OF TRANSPORTATION
Research and Special Programs Administration
49 CFR Parts 171, 173 and 180
[Docket No. RSPA-03-14405 (HM-220F)]
RIN 2137-AD78

Hazardous Materials Regulations: Aluminum Cylinders Manufactured
of Aluminum Alloy 6351-T6 Used in SCUBA, SCBA, and Oxygen Service--
Revised Requalification and Use Criteria

AGENCY: Research and Special Programs Administration (RSPA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: RSPA proposes to amend requirements in the Hazardous Materials
Regulations (HMR; 49 CFR Parts 171-180) pertaining to aluminum
cylinders manufactured using aluminum alloy 6351-T6. The purpose of
this rulemaking initiative is to enhance safety, minimize the potential
for personal injury and property damage during the cylinder filling
process, and adopt a standard for early detection of sustained load
cracking (SLC) to reduce the risk of a cylinder rupture.

DATES: Comments must be received by November 10, 2003.

ADDRESSES: You may submit comments by any of the following methods:
? Web Site: http://dms.dot.gov. Follow the instructions
for submitting comments on the DOT electronic docket site.
? Fax: 1-202-493-2251.
? Mail: Docket Management System; U.S. Department of
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401,
Washington, DC 20590-001.
? Hand Delivery: To the Docket Management System; Room PL-401
on the plaza level of the Nassif Building, 400 Seventh Street, SW.,
Washington, DC between 9:00 am and 5:00 pm, Monday through Friday,
except Federal Holidays.
Instructions: You must include the agency name and docket number
RSPA -03-14405 (HM-220F) or the Regulatory Identification Number (RIN)
for this notice at the beginning of your comment. For detailed
instructions on submitting comments and additional information on the
rulemaking process, see the Public Participation section of this
document. Note that all comments received will be posted without change
to http://dms.dot.gov including any personal information
provided. Please see the Privacy Act section of this document.
Docket: You may view the public docket through the Internet at
http://dms.dot.gov or in person at the Docket Management
System office at the above address.

FOR FURTHER INFORMATION CONTACT: Mark Toughiry, Office of Hazardous
Materials Technology, (202) 366-4545, or Charles E. Betts, Office of
Hazardous Materials Standards, (202) 366-8553; RSPA, U.S. Department of
Transportation, 400 Seventh Street SW., Washington, DC 20590-0001.

SUPPLEMENTARY INFORMATION:

Contents

I. Background
II. Public Participation
III. Section-By-Section Review
IV. Regulatory Analyses and Notices
A. Executive Order 12866 and DOT Regulatory Polices and
Procedures
B. Executive Order 13132
C. Executive Order 13175
D. Regulatory Flexibility Act, Executive Order 13272, and DOT
Procedures and Policies
E. Paperwork Reduction Act
F. Regulation Identifier Number (RIN)
G. Unfunded Mandates Reform Act
H. Environmental Assessment
I. Privacy Act

I. Background

Cylinders made of aluminum alloy 6351-T6 are known to be
susceptible to sustained load cracking (SLC) in the neck and shoulder
area of the cylinder. The majority of the SLC-related ruptures have
occurred in self-contained underwater breathing apparatus (SCUBA),
self-contained breathing apparatus (SCBA), and oxygen services. Since
1994, the Research and Special Programs Administration (RSPA, we) has
been notified of twelve suspected SLC ruptures of cylinders
manufactured of aluminum alloy 6351-T6. Five of the twelve ruptures
resulted in serious injuries. RSPA's review of manufacturers' data
revealed that there have been several thousand cylinders

[[Page 53315]]

that leaked, and many additional cylinders have been found with cracks
in the cylinder's neck during the normal requalification process.
Manufacturers of cylinders made from the 6351-T6 alloy have performed
research, testing and analysis to determine whether there is any
correlation between SLC and the probability of a cylinder rupture. The
data indicated that the cylinders would leak but not rupture when
operated at marked service pressure. It was also found that the
probability of cracking increases with an increase in stress levels. We
performed additional metallurgical analysis on several ruptured
cylinders to verify the cause of failure and failure mode. (See the
metallurgical analysis reports at http://hazmat.dot.gov/3al_cyls_info.htm.)
Those metallurgical analyses revealed that SLC caused the
cylinder ruptures, but the results were inconclusive as to why the
cylinders abruptly ruptured instead of leaked. United States
manufacturers discontinued using aluminum alloy 6351-T6 in mid-1990,
replacing it with aluminum alloy 6061-T6, which is not susceptible to
SLC. We estimate that approximately four million U.S. cylinders
manufactured from aluminum alloy 6351-T6 are in use in SCUBA, SCBA, and
oxygen services.
The primary domestic manufacturers of DOT 3AL cylinders currently
in service are Luxfer USA; Walter Kidde Co.; Cliff Impact Division of
Parker Hannifin Corporation; and Catalina Cylinders. The majority of
the cylinders are being used in six major services: (1) SCUBA, (2)
SCBA, (3) carbon dioxide, (4) oxygen, (5) industrial gases, and (6)
fire extinguishers.
Cylinders manufactured of aluminum alloy 6351-T6 prior to July 1990
include seamless aluminum cylinders marked ``DOT 3AL'', including those
marked with ``DOT 3AL'' above or near one of the following exemption or
special permit numbers: 6498, 7042, 8107, 8364, and 8422. In addition,
unless determined otherwise, affected individuals should assume that a
DOT 3AL or DOT-E 7235 cylinder manufactured outside the United States
is constructed of aluminum alloy 6351-T6.
On August 8, 2002, we published a final rule (Docket HM-220D, 67 FR
51626) that amended the requirements of the HMR applicable to the
maintenance, requalification, repair, and use of DOT specification
cylinders. In that final rule, we added the following amendments
pertaining to DOT specification cylinders made with aluminum alloy
6351-T6:
? We removed the authorization for the manufacture of DOT
specification cylinders from aluminum alloy 6351-T6 because cylinders
manufactured with this aluminum alloy have a greater risk of failure
than other aluminum cylinders.
? We prohibited these cylinders for Hazard Zone A materials
effective on October 1, 2002. After that date, cylinders made of
aluminum alloy 6351-T6 may not be filled and offered for transportation
in toxic inhalation hazard service.
? We prohibited the use of cylinders manufactured of aluminum
alloy 6351-T6 for gases having pyrophoric properties.
? We required a DOT specification or exemption cylinder made
of aluminum allow 6351-T6 to be inspected for evidence of sustained
load cracking in the neck and shoulder area.
As stated earlier, the majority of the SLC-related ruptures
occurred in SCUBA, SCBA and oxygen services. Additionally, for these
services, the probability of cracking increases due to the increased
frequency with which cylinders in these services are filled. We
recognize that cylinders used in beverage service are also filled on a
frequent basis. However, beverage service cylinders typically are
filled to lower pressures than cylinders used in SCUBA, SCBA, and
oxygen services, thereby reducing the stress levels to which beverage
service cylinders are subjected. Moreover, in SCUBA and SCBA services,
the cylinder is attached to the back of a diver or firefighter, which
substantially increases the risk of injury or fatality in the event of
a rupture. Similarly, an oxygen cylinder may be placed close to a
patient in the hospital or home. SLC could also result in an oxygen
leak that may cause an explosion. Therefore, because of the higher risk
in SCUBA, SCBA and oxygen services, this rulemaking (HM-220F) proposes
to adopt a standard for early detection of SLC to reduce the risk of a
cylinder rupture.
We performed an analysis of costs associated with operating
cylinders manufactured of aluminum alloy 6351-T6. The economic
evaluation considered and compared the costs of three possible
alternatives: (1) Leaving the cylinder in service without taking any
additional measures to reduce the risk, (2) removing all cylinders made
of aluminum alloy 6351-T6 from service, or (3) performing a non-
destructive examination (NDE) at the time of the cylinder's periodic
requalification and requiring additional operational controls (OC)
during the cylinder filling process. Estimating the societal cost of
injuries or fatalities that would otherwise be avoided if SLC were
eliminated is complicated. The uncertainties due to the
unpredictability at which ruptures occur and the likelihood that aging
cylinders may be progressively more prone to SLC makes option three to
most prudent of the three options. It also addresses a known safety
problem without imposing excessive costs.
DOT 3AL cylinders must be requalified every five years (twelve
years for fire extinguishers) in accordance with Sec. 180.205 of the
HMR. The requalification performed under Sec. 180.205 includes a
visual inspection (internal and external) and a volumetric expansion
test. The requalification does not include a specific NDE of the
cylinder neck or crown areas for detection of SLC. However, we
understand that in addition to the visual inspection and volumetric
expansion test, many users and requalifiers are currently performing an
eddy current examination. Approximately 2,000 eddy current devices have
been purchased by various cylinder requalifiers to examine aluminum
cylinders for SLC. Cylinder manufacturers report that a large number of
affected cylinders have been removed from service because of flaws
discovered during eddy current examinations.
We evaluated three NDE methods--visual examination (VT), eddy
current examination (ET), and ultrasonic examination (UT)--to detect a
critical-size crack. A cylinder with a critical-size crack must be
removed from service upon detection of the crack. Under the direction
of RSPA, Texas Research Institute (TRI) evaluated these three NDE (VT,
ET, UT) methods by performing blind examinations that were applied by
individuals of varying skill levels (See the Nondestructive Inspection
of High Pressure Aluminum Gas Cylinder, Final Report, dated September
2000, at http://hazmat.dot.gov/ohmforms.htm#other). TRI
determined that each NDE method was capable of detecting SLC, but the
detectability using VT was limited by external factors, such as the
inspector's eye sight, lighting, position of the crack, and alertness of
the examiner. TRI also determined that UT must be applied by a certified
technician to produce accurate results in detecting SLC. TRI concluded
that ET combined with a visual inspection (VT) provides the most accurate
and practical examination for detecting SLC. Both ET and VT can be
conducted by a requalifier with minimal training.
In this NPRM, we propose to require cylinders manufactured of
aluminum alloy 6351-T6 used in SCUBA (diving), SCBA (firefighting), and
oxygen service

[[Page 53316]]

to undergo a combined visual and eddy current examination (referred to
as ``VE'' in this rulemaking) in order to requalify the cylinders in
accordance with Sec. 180.205. We propose to add a new Appendix C to
part 180, to specify the procedure to be used to conduct the ET
examination. No person may requalify a DOT specification or exemption
cylinder in accordance with Sec. 180.209 of this chapter unless that
person has been issued a requalifier identification number (RIN) as
provided in Sec. 107.805(d). Each person who holds a valid RIN and
performs an ET in accordance with Sec. 180.205 must notify RSPA in
writing in accordance with the procedural requirements in Sec.
107.805. We are also proposing that suitable safeguards be provided to
protect personnel and facilities should failure occur during the
filling of cylinders manufactured of aluminum alloy 6351-T6 used in
SCUBA, SCBA, and oxygen services. Additionally, we are recommending
that only individuals essential to the filling process be allowed in
the vicinity of the cylinder during the filling process.
Although we believe that the twelve reported SLC suspected ruptures
under-represent the extent of the SLC issue, we do not have sufficient
data to determine whether the SLC related ruptures extend beyond those
services discussed above. Therefore, we are requesting additional
information from manufactures and users who are aware of the rupture of
any DOT 3AL cylinder or any other cylinder manufactured from aluminum
alloy 6351-T6, whether the incident was domestic or foreign, to submit
the information in their comments to this rulemaking. More broadly, we
invite commenters to address the issue of whether the new inspection
requirements proposed in this NPRM should apply to cylinders
manufactured of aluminum alloy 6351-T6 and used in services other than
SCUBA, SCBA, or oxygen.

II. Public Participation

You should identify the docket number RSPA-03-14405 (HM-220F) at
the beginning of your comments. You should submit two copies of your
comments, if you submit them by mail. If you wish to receive
confirmation that RSPA received your comments, you should include a
self-addressed stamped postcard. Internet users may access all comments
received by DOT at http://dms.dot.gov.

III. Section-by-Section Review

Part 171

Section 171.7

As a result of RSPA's proposal to require cylinders manufactured of
aluminum alloy 6351-T6 used in SCUBA, SCBA, and oxygen service to
undergo an NDE, we are proposing to revise the incorporation by
reference entry CGA Pamphlet C-6.1, ``Standards for Visual Inspection
of High Pressure Aluminum Compressed Gas Cylinders, 1995,'' under the
Compressed Gas Association, Inc., to incorporate by reference the 2002
edition of this pamphlet. The 2002 edition of the standard has
provisions discussing cleaning methods that may result in the removal
of cylinder wall material. It also contains a new requirement that all
aluminum cylinders be internally inspected for cracks in the neck
region. Persons who may be affected by these changes should review the
standard to determine any potential impacts on their operations.

Part 173

Section 173.302

We are proposing to revise this section by adding a new paragraph
(e) to require that operational controls must be in place during the
filling process, for cylinders manufactured of aluminum alloy 6351-T6.
The operational controls will reduce the risk of injury and property
damage during the filling process.

Part 180

Section 180.209

We are proposing to revise in paragraph (a), the entry for the DOT
3AL cylinder in the ``Requalification of Cylinders'' table to add a
reference to the new paragraph (m). In addition, we are proposing to
add a new paragraph (m) to include a non-destructive examination for
cylinders manufactured of aluminum alloy 6351-T6. The non-destructive
examination will be used to detect sustained load cracking in the neck
and shoulder area.

Section 180.213

We are proposing to revise paragraph (d) and to add a new paragraph
(f)(8) to specify the requalification marking requirements for those
aluminum cylinders that successfully pass the combined eddy current
examination and visual inspection.

IV. Regulatory Analyses and Notices

A. Executive Order 12866 and DOT Regulatory Policies and Procedures

This proposed rule is not considered a significant regulatory
action under section 3(f) of Executive Order 12866 and, therefore, was
not reviewed by the Office of Management and Budget. The proposed rule
is not considered a significant rule under the Regulatory Policies and
Procedures of the Department of Transportation [44 FR 11034]. A
regulatory analysis is available for review in the docket.
The compliance costs associated with this rule are minimal. The
regulatory analysis revealed the increased cost for performing an NDE
and OC to be small compared to the cost and safety risks of ``doing
nothing,'' and it is significantly less than the cost of ``removing all
cylinders from service.'' The economic evaluation data were based on
information obtained from cylinder manufacturers, industrial gas
companies, cylinder inspectors, and on metallurgical evaluation of the
ruptured cylinders. We determined that the removal of cylinders
manufactured of aluminum alloy 6351-T6 will result in a significant
economic impact to cylinder owners and may cause a serious shortage of
breathing air cylinders used in fire fighting and medical applications.
Therefore, based on the risk assessment and regulatory analysis, we
conclude that a requirement to perform an eddy current examination
combined with a visual inspection at the required five-year
requalification period is the best alternative. Since the NDE would
take place at the time of the currently required five-year
requalification period, the cost would be reduced substantially. We
estimate the cost of volumetric expansion test and internal visual
inspection that is required under the current regulation to be $5.00
per cylinder every five years. We estimate that the eddy current
examination combined with the current volumetric expansion test and
visual inspection to be $7.25 per cylinder every five years. The
estimated $7.25 per cylinder includes the initial start-up cost (e.g.,
training and cost of purchasing eddy current equipment). Therefore, we
estimate the additional annual cost of the eddy current examination
combined with the visual inspection to be $0.45 per cylinder. The
average annual cost of this examination is the annual cost per cylinder
multiplied by the number of cylinders, or $1,800,000. The cost of
additional operational controls is nominal.

[[Page 53317]]

While researching a viable NDE method that could accurately detect
SLC, we made a significant effort to reduce the risk of injury by
educating cylinder users regarding the risk of using cylinders
manufactured of aluminum alloy 6351-T6. As a result of this effort, we
published the following safety advisory notices in the Federal Register
between 1983 and 1999, concerning SLC in cylinders manufactured of
aluminum alloy 6351-T6:
Aug. 11, 1983; Vol. 48, No. 156; pg. 36559
Feb. 27, 1984; Vol. 49, No. 39; pg. 7182
Nov. 01, 1984; Vol. 49, No. 213; pg. 44047
Jul. 17, 1985; Vol. 50, No. 137; pg. 29037
Aug. 15, 1985; Vol. 50, No. 158; pg. 32944
Jul. 10, 1987; Vol. 52, No. 132; pg. 26027
Mar. 24, 1993; Vol. 58, No. 55; pg. 15895
Aug. 10, 1993; Vol. 58, No. 152; pg. 42620
Jul. 26, 1994; Vol. 59, No. 142; pg. 38028
Dec. 14, 1998; Vol. 63, No. 239; pg. 68819
Oct. 18, 1999; Vol. 64, No. 2001; pg. 56243

B. Executive Order 13132

This proposed rule has been analyzed in accordance with the
principles and criteria contained in Executive Order 13132
(``Federalism''). This proposed rule would preempt State, local and
Indian tribe requirements, but does not propose any regulation that has
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 material transportation law, 49 U.S.C. 5101-
5127, contains an express preemption provision (49 U.S.C. 5125(b)) that
preempts State, local, and Indian tribe requirements on certain covered
subjects. Covered subjects are:
(1) The designation, description, and classification of hazardous
material;
(2) the packing, repacking, handling, labeling, marking, and
placarding of hazardous material;
(3) the preparation, execution, and use of shipping documents
related to hazardous material 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; or
(5) the design, manufacturing, fabricating, marking, maintenance,
reconditioning, repairing, or testing of a packaging or container
represented, marked, certified, or sold as qualified for use in
transporting hazardous material.
This proposed rule covers items 2 and 5 and would preempt any
State, local, or Indian tribe requirements not meeting the
``substantively the same'' standard.
Federal hazardous materials transportation law provides at Sec.
5125(b)(2) that, if the Secretary of Transportation issues a regulation
concerning any of the covered subjects, the Secretary must determine
and publish in the Federal Register the effective date of Federal
preemption. The effective date may not be earlier than the 90th day
following the date of issuance of the final rule and not later than two
years after the date of issuance. We propose that the effective date of
Federal preemption will be 90 days from publication of a final rule in
the Federal Register.

C. Executive Order 13175

This proposed rule has been analyzed in accordance with the
principles and criteria contained in Executive Order 13175
(``Consultation and Coordination with Indian Tribal Governments'').
Because this proposed rule does not have tribal implications, does not
impose substantial direct compliance costs, and is not required by
statute, the funding and consultation requirements of Executive Order
13175 do not apply.

D. 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 a rule is not expected to have a
significant economic impact on a substantial number of small entities.
This rule imposes only minimal new costs of compliance on the regulated
industry. Based on the assessment in the regulatory evaluation, I
hereby certify that while this rule applies to a substantial number of
small entities, there will not be a significant economic impact on
those small entities. A detailed Regulatory Flexibility analysis is
available for review in the docket.
This proposed rule has been developed in accordance with Executive
Order 13272 (``Proper Consideration of Small Entities in Agency
Rulemaking'') and DOT's procedures and policies to promote compliance
with the Regulatory Flexibility Act to ensure that potential impacts of
draft rules on small entities are properly considered.

E. Paperwork Reduction Act

This proposed rule may result in a modest increase in annual burden
and costs based on a new information collection requirement. These
proposals regarding the shipment of aluminum cylinders which result in
a new information collection requirement will be submitted to OMB for
review and approval. RSPA currently has an approved information
collection under OMB Control No. 2137-0022, ``Testing, Inspection, and
Marking Requirements for Cylinders.''
Section 1320.8(d), Title 5, Code of Federal Regulations requires
that RSPA provide interested members of the public and affected
agencies an opportunity to comment on information collection and
recordkeeping requests. This notice identifies a new information
collection request that RSPA will submit to OMB for approval based on
the requirements in this proposed rule. RSPA has developed burden
estimates to reflect changes in this proposed rule. RSPA estimates that
the total information collection and recordkeeping burden as proposed
in this rule would be as follows:
OMB No. 2137-0022:
Total Annual Number of Respondents: 139,352.
Total Annual Responses: 153,287.
Total Annual Burden Hours: 271,461.
Total Annual Burden Cost: $2,615,515.
Total One-Time Start-Up Cost: $964,000.
RSPA specifically requests comments on the information collection
and recordkeeping burdens associated with developing, implementing, and
maintaining these requirements for approval under this proposed rule.
Direct your requests for a copy of the information collection to
Deborah Boothe or T. Glenn Foster, Office of Hazardous Materials
Standards (DHM-10), Research and Special Programs Administration, Room
8102, 400 Seventh Street, SW., Washington, DC 20590-0001, Telephone
(202) 366-8553.
Address written comments to the Dockets Unit as identified in the
ADDRESSES section of this rulemaking. We must receive your comments
prior to the close of comment period identified in the DATES section of
this rulemaking. Under the Paperwork Reduction Act of 1995, no person
is required to respond to an information collection unless it displays
a valid OMB control number. If these proposed requirements are adopted
in a final rule, RSPA will submit the revised information collection
and recordkeeping requirements to the

[[Page 53318]]

Office of Management and Budget for approval.

F. Regulation Identifier Number (RIN)

A regulation identifier number (RIN) is assigned to each regulatory
action listed in the Unified Agenda of Federal Regulations. The
Regulatory Information Service Center publishes the Unified Agenda in
April and October of each year. The RIN number contained in the heading
of this document can be used to cross-reference this action with the
Unified Agenda.

G. Unfunded Mandates Reform Act

This proposed rule does not impose unfunded mandates under the
Unfunded Mandates Reform Act of 1995. It does not result in costs of
$100 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.

H. Environmental Assessment

The National Environmental Policy Act of 1969 (NEPA), as amended
(42 U.S.C. 4321-4347), requires Federal agencies to consider the
consequences of major federal actions and prepare a detailed statement
on actions significantly affecting the quality of the human
environment. There are no significant environmental impacts associated
with this proposed rule. RSPA proposes to amend requirements in the HMR
pertaining to DOT 3AL aluminum cylinders. The purpose of this
rulemaking initiative is to minimize personal injury during the
cylinder filling process and to adopt a standard for early detection of
sustained load cracking in order to reduce the risk of a cylinder
rupture. Adopting a standard for early detection of sustained load
cracking in order to reduce the risk of a cylinder rupture has no
potential for environmental damage or contamination.

I. Privacy Act

Anyone is able to search the electronic form of all comments
received into any of our dockets by the name of the individual
submitting the comment (or signing the comment, if submitted on behalf
of an association, business, labor union, etc.). You may review DOT's
complete Privacy Act Statement in the Federal Register published on
April 11, 2000 (Volume 65, Number 70; Pages 19477-78) or you may visit
http://dms.dot.gov.

List of Subjects

49 CFR Part 171

Exports, Hazardous materials transportation, Hazardous waste,
Imports, Incorporation by reference, 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 180

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

In consideration of the foregoing, we propose to amend 49 CFR
Chapter I, Subchapter C, as follows:

PART 171--GENERAL INFORMATION, REGULATIONS, AND DEFINITIONS

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

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

2. In Sec. 171.7, in the table in paragraph (a)(3), the entry for
pamphlet C-6.1 under the Compressed Gas Association, Inc., is revised
to read as follows:

Sec. 171.7 Reference material.

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

----------------------------------------------------------------------------------------
Source and name of material 49 CFR reference
----------------------------------------------------------------------------------------

* * * * * * *
Compressed Gas Association, Inc.,

* * * * * * *
CGA Pamphlet C-6.1, Standards for Visual 180.205; 180.209; Appendix C to part 180.
Inspection of High Pressure Aluminum
Compressed Gas Cylinders, 2002.

* * * * * * *
-----------------------------------------------------------------------------------------

PART 173--SHIPPERS--GENERAL REQUIREMENTS FOR SHIPMENT AND PACKAGES

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

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

4. In Sec. 173.302, paragraph (e) is added to read as follows:

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

* * * * *
(e) Aluminum cylinders manufactured of 6351-T6 aluminum alloy.
Suitable safeguards must be provided to protect personnel and
facilities should failure occur while filling cylinders manufactured of
aluminum alloy 6351-T6 used in self-contained underwater breathing
apparatus (SCUBA), self-contained breathing apparatus (SCBA), and
oxygen services. The cylinder filler should allow only those
individuals essential to the filling process to be in the vicinity of
the cylinder during the filling process.

PART 180--CONTINUING QUALIFICATION AND MAINTENANCE OF PACKAGINGS

5. The authority citation for part 180 continues to read as
follows:

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

6. In Sec. 180.209 in paragraph (a), in the ``Requalification of
Cylinders table'' the entry ``DOT 3AL'' is revised, and a new paragraph
(m) is added to read as follows:

Sec. 180.209 Requirements for requalification of specification
cylinders.

* * * * *
(a) * * *

[[Page 53319]]

Table 1.--Requalification of Cylinders \1\
------------------------------------------------------------------------
Minimum test
Specification under which pressure (psig.) Requalification
cylinder was made \2\ period (years)
------------------------------------------------------------------------

* * * * * * *
DOT 3AL......................... 5/3 times service 5 or 12 (see Sec.
pressure. 180.209(j) and
Sec. 180.209(m)
\3\).

* * * * * * *
------------------------------------------------------------------------
\1\ Any cylinder not exceeding 2 inches outside diameter and less than 2
feet in length is excepted from volumetric expansion test.
\2\ For cylinders not marked with a service pressure, see Sec.
173.301(e)(1) of this subchapter.
\3\ This provision does not apply to aluminum cylinders used in fire
extinguisher service.

* * * * *
(m) Aluminum cylinders manufactured of 6351-T6 aluminum alloy. In
addition to the periodic requalification and marking described in Sec.
180.205, cylinders manufactured of aluminum alloy 6351-T6 used in self-
contained underwater breathing apparatus (SCUBA), self-contained
breathing apparatus (SCBA), and oxygen service must be requalified and
inspected for sustained load cracking in accordance with the non-
destructive examination method described in the following table.
Cylinders with sustained load cracking that has expanded into the neck
threads must be condemned in accordance with Sec. 180.205(i). This
provision does not apply to aluminum cylinders used in fire
extinguisher service and to cylinders used to transport carbon dioxide
or industrial gases. Requalification and inspection of the aluminum
cylinders must conform to the following table.

Requalification and Inspection of Aluminum Cylinders Made of Aluminum Alloy 6351-T6 Manufactured Prior to July
1990
----------------------------------------------------------------------------------------------------------------
Sustained load cracking Requalification
Requalification requirement Examination procedure \1\ rejection criteria \2\ period (years)
----------------------------------------------------------------------------------------------------------------
Eddy current examination combined with In accordance with 2 threads long........... 5
visual inspection. Appendix C of this part.
Visual inspection--In
accordance with CGA
Pamphlet C-6.1 (IBR; see
Sec. 171.1 of this
subchapter).
----------------------------------------------------------------------------------------------------------------
\1\ The requalifier performing eddy current must be familiar with the eddy current equipment and standardize
(calibrate) the system in accordance with the requirements provided in Appendix C to this part. The
requalifier must perform the visual inspection of the cylinder neck and shoulder in accordance with CGA
Pamphlet C-6.1 (IBR; see Sec. 171.7 of this subchapter).
\2\ The eddy current must be applied from the inside of the cylinder's neck to detect any sustained load
cracking that has expanded into the neck threads.

7. In Sec. 180.213, paragraph (d) is revised and a new paragraph
(f)(8) is added to read as follows:

Sec. 180.213 Requalification markings.

* * * * *
(d) Requalification markings. Each cylinder that has successfully
passed requalification must be marked with the RIN set in a square
pattern, between the month and year of the requalification date. The
first character of the RIN must appear in the upper left corner of the
square pattern; the second in the upper right; the third in the lower
right; and the fourth in the lower left. Example: A cylinder
requalified in September 1998, and approved by a person who has been
issued RIN ``A123'', would be marked plainly and permanently into the
metal of the cylinder in accordance with location requirements of the
cylinder specification or on a metal plate permanently secured to the
cylinder in accordance with paragraph (b) of this section. An example
of the markings prescribed in this paragraph (d) is a follows:
[GRAPHIC]
[TIFF OMITTED]
TP10SE03.000

Where:

``9'' is the month of requalification
``A123'' is the RIN
``98'' is the year of requalification, and
``X'' represents the symbols described in paragraphs (f)(2) through
(f)(8) of this section.
* * * * *
(f) * * *
* * * * *
(8) For designation of the eddy current examination combined with a
visual inspection, the marking is as illustrated in paragraph (d) of
this section, except that the ``X'' is replaced with the letters
``VE''.
8. In Part 180, Appendix C is added to read as follows:

Appendix C to Part 180--Acceptable Eddy Current Examination for
Cylinders Manufactured of Aluminum Alloy 6351-T6

1. This examination procedure is designed to detect critical
size cracks in cylinders made of aluminum alloy 6351-T6.
2. Eddy Current Equipment--Equipment, such as Visual Plus,
Visual Eddy, or equivalent non-destructive testing equipment must be
capable of detecting the notches on the standard reference ring.
3. Eddy Current Reference Ring--The reference ring must be
produced to represent the outer diameter (O.D.) of each cylinder to
be tested. The reference ring must include artificial notches that
will simulate a neck crack. The size of the artificial notch (depth
and length) must be obtained from the eddy current equipment
manufacturer. The standard reference must have a drawing that
includes the depth of each notch, diameter and alloy.
4. Eddy Current Equipment Standardization--Each day prior to
testing, the eddy current equipment must be standardized for each
size (O.D.) of aluminum cylinder, using the reference ring described
in item number 3 above. The minimum standardization requirements of
the eddy current equipment are as follows:

[[Page 53320]]

(i) Screw reference ring onto the probe until the base of the
reference ring is flush with the probe bottom, then back off two
turns.
(ii) Warm the equipment for at least 20 minutes.
(iii) Set up the system between 150-215 kHz.
(iv) Locate the line \1/4\ from the screen bottom.
(v) Rotate the reference ring counterclockwise and observe the
spike signal on the screen. Adjust the gain (using gain control)
until the spike peaks to \3/4\ of the screen height (from home
position to \1/4\ of screen from the top).
(vi) When spike signals break the centerline the threshold light
must come on.
5. Eddy Current Examination and Visual Inspection--A written
examination procedure for performing the eddy current examination
and visual inspection must be kept at each facility that performs
examinations under this procedure. The visual inspection procedure
must be in accordance with CGA pamphlet C-6.1 (IBR; see Sec. 171.1
of this subchapter).
At a minimum, the written examination procedure for performing
the eddy current must include the following instructions:
(i) Remove the probe from the reference ring and screw probe
clockwise half-way into cylinder's neck and press the sweep (e.g.
NULL) button.
(ii) Continue rotating the probe clockwise until the threshold
line moves off top of the screen, indicating probe is inside
shoulder area (probe is in air).
(iii) Rotate probe counterclockwise towards the outlet of the
cylinder until the threshold line appears on the screen indicating
the probe is in the cylinder's neck.
(iv) Press the sweep (e.g. NULL) button to ensure that the line
is positioned on screen, preferably at home position.
(v) Watch for spike signals indicating cracks. Mark positions
with a grease pencil. When the spike occurs rotate the probe 360
degrees.
(vi) Check for successive indications at same angle indicating
multiple cracks. Two successive spikes that break the threshold at
the same angle indicate a two thread crack. A two thread crack is
the rejection criteria.
(vii) Perform the visual inspection for confirmation.
6. Examination equipment records.
Records of eddy current inspection shall contain the following
information:
(i) Equipment manufacturer, model number and serial number.
(ii) Probe description and unique identification (e.g., serial
number, part number, etc.).
7. Eddy current examination reporting and record retention
requirements.
Daily records of eddy current examinations must be maintained by
the person who performs the requalification until either the
expiration of the requalification period or until the cylinder is
again requalified, whichever occurs first. These records must be
made available for inspection by a representative of the Department
on request. Eddy current examination records shall contain the
following information:
(i) Specification of each standard reference ring used to
perform the eddy current examination.
(ii) DOT specification or exemption number, manufacturer's name
or symbol, owner's name or symbol and date of manufacture.
(iii) Name of test operator performing the eddy current
examination.
(iv) Date of eddy current examination.
(v) Location and type of defect on the cylinder crown or the
threaded neck (e.g., 5 threads).
(vi) Acceptance/rejection results (e.g. pass or fail).
(vii) Legible identification of test operator.

Issued in Washington, DC on September 3, 2003, under authority
delegated in 49 CFR part 106.
Frits Wybenga,
Deputy Associate Administrator for Hazardous Materials Safety.

[FR Doc. 03-22808 Filed 9-9-03; 8:45 am]
BILLING CODE 4910-60-P

Notices For
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994

Hazardous Materials Regulations: Aluminum Cylinders Manufactured of Aluminum Alloy 6351-T6 Used in SCUBA, SCBA, and Oxygen Service-- Revised Requalification and Use Criteria

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