# Airgas SAFECOR — Hazardous Materials Safety Interpretation

- **operation:** document
- **citation:** 13-0004
- **title:** Airgas SAFECOR — Hazardous Materials Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2013-08-21
- **effective on:** Not available
- **summary:** 13-0004 response to Airgas SAFECOR concerning 180.209.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-13-0004.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-13-0004.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-13-0004
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2013/130004.pdf
**body:**

<<<PAGE 1>>>

U.S. Department of Transportation
Pipeline and Hazardous Materials
Safety Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
AUG 2 1 2013
Mr. John Anderson
Airgas SAFECOR
P.O. Box 20067
Cheyenne, WY 82003
Ref. No.: 13-0004
Dear Mr. Anderson:
This is in response to your December 20,2012 email and conversation with a member of my
staff concerning visual inspection requirements under the Hazardous Materials Regulations
(HMR; 49 CFR Parts 171-180). Specifically, you cite a potential conflict between a letter
this office issued in 2011 (Ref. No 10-0077) and Compressed Gas Association Publication
C-6 Standards for Visual Inspection of Compressed Gas Cylinders (CGA C-6). Cylinders
that conform to the requirements of§ 180.209(g) are exempt from the hydrostatic test by
virtue of their exclusive use in cetiain noncorrosive gas service. However, these cylinders
must be given a complete visual inspection in accordance with CGA C-6. In interpretation
10-0077, we stated that no measurement of the tare weight is required for the external visual
inspection. The letter went on to say that when the cylinder exhibits corrosion, the cylinder
must be fmiher examined for condemnation.
This guidance provided in 10-0077 is correct. If corrosion is identified during the external
visual inspection then the cylinder may be evaluated using the four general criteria in Section
3.2.1.1 ofCGA C-6 to determine ifthe cylinder should be condemned. Section 3.2.1.1,
paragraph ( 1 ), in part, states that the cylinder must be condemned when the tare weight is less
than 90% of the original stamped tare weight. Additionally. even if a cylinder satisfies the
tare weight criteria of 3.2.1.1 paragraph 1, it must still be further examined by measuring the
wall thickness in accordance with 3.2.1.1 paragraphs (2), (3) or ( 4) for the types of corrosion
that has been identified on the cylinder. However, if as a result of a visual inspection the
cylinder does not exhibit corrosion and it meets the requirements for exclusive use in
§ 180.209(g), the cylinder will meet the four general criteria in 3.2.1.1. Thus verification of
the tare weight is not necessary.
I hope this information is helpful. If you have further questions, please do not hesitate to
contact this office.
Dl?i -
Delmer Billings ~
Senior Regulatory Advisor
Standards and Ru1emaking Division

<<<PAGE 2>>>

U.S. Department
of Transportation
Pipeline and Hazardous
Materials Safety
Administration
1200 New Jersev Avenue SE
Washington. DC. 20590
Mr. Fred A. Nachman
President
Thunderbird Cylinder
4209 E. University Drive
Phoenix, AZ 85034-7315
Ref. No.: 10-0077
Dear Mr. Nachman:
This responds to your letter requesting clarification of the requirements concerning the tare
weight of liquefied petroleum gas (LPG) cylinders under the Hazardous Materials Regulations
(HMR; 49 CFR Parts 171-180).
Q 1. Does a low pressure (LPG) cylinder being visually inspected need to have its
valve/PRD removed to verify there is no liquid inside it that would result in improper
tare weight verification?
AI. No. A cylinder conforming to §180.209 used exclusively in LPG service may be
given an external visual inspection in lieu of a hydrostatic test. No measurement of
the tare weight is required for the external visual inspection. When the cylinder
exhibits corrosion, the cylinder must be further examined for condemnation. The
cylinder must be examined by measuring tare weight in accordance with CGA C-6,
5.2.1.1 (1). The cylinder must be empty. The tare weight is measured with the valve/
PRD connected. Cylinders exempt from tare weight measurement must be examined
by measuring wall thickness in accordance with CGA C-6, 5.2.1.1 (2), (3), or (4).
Q2. At the time of requalification, should the pressure relief device (PRD} be changed?
A2. No. There is no regulatory requirement to change the PRD at the time of
requalification. Pressure relief devices must be tested for leaks before a filled cylinder
is shipped in accordance with §173.301(a)(2) and (3).
Q3. Should it even be an option to hydrostatically test or steam clean LPG cylinders when
ethyl mercaptan exposed to water/moisture is corrosive?

<<<PAGE 3>>>

A3. Cylinders containing LPG in accordance with § 180.209(g) may be given an external
visual inspection in lieu of a hydrostatic pressure test. This would avoid adding
moisture to the cylinder. If steam cleaning is used, it is the responsibility of the filler
to make sure the cylinder is dry before filling with a hazardous material, if moisture is
dangerous to the cylinder(§ 173.301(d)).
I hope this information is helpful. If we can be of further assistance, please contact us.
Sincerely,
(/2~ c--~ /.~ J_ ------
~<~o/~
Ben Supko
Chief, Standards Development Branch
Standards and Rulemaking Division

<<<PAGE 4>>>

Drakeford, Carol
From:
Sent:
To:
Cc:
Subject:
Attachments:
Foster, Glenn (PHMSA)
Thursday, December 20, 2012 12:22 PM
Drakeford, Carolyn (PHMSA)
Benedict, Robert (PHMSA); Betts, Charles (PHMSA); Billings, Delmer (PHMSA); Foster, Glenn
(PHMSA); Kelley, Shane (PHMSA); Pfund, Duane (PHMSA); Supko, Ben (PHMSA)
FW: Request for further clarification on Letter of Interpretation 10-0077
Letter of Interpretation Tare Weight. pdf
Carolyn,
Please process the attached as a request for letter of interpretation.
Thanks,
Glenn
From: John Anderson (SAFECOR) [mailto:John.Anderson.SAFECOR@Airgas.com]
Sent: Thursday, December 20, 2012 12:20 PM
To: Foster, Glenn (PHMSA)
Subject: Request for further clarification on Letter of Interpretation 10-0077
Good morning Mr. Foster
Request for further clarification on Letter of Interpretation 10-0077
On the attached Letter of Interpretation (1 0-0077) under answer A 1 it states "No measurement of the tare weight is required
for the external visual inspection". The Letter goes on to state that the cylinder must be examined by measuring tare
weight in accordance with C-6.
The 1993 edition of CGA C-6 is the edition that is incorporated by reference and section 3.2.1.1 paragraph 1 states that the
cylinder must be condemned when the original tare weight is less than 90% of the original stamped tare weight. It goes on
to state that if the tare weight is less than 95% of the original stamped tare weight the cylinder can not be visually inspected
it must be tested by water jacket or direct expansion.
Can you please clarify this conflict between the Letter of Interpretation and what is stated in CGA C-6? that the tare weight measurement/accuracy is part of the cylinder requalification process
C-6 clearly states
Thank you,
John Anderson
Airgas SAFECOR
P.O. Box 20067
Cheyenne, WY 82003
Phone 1-307-778-8809
Fax 1-307-778-7497
john. anderson@airgas. com
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