# Precision Fabricators Ltd. — Hazardous Materials Safety Interpretation

- **operation:** document
- **citation:** 17-0137
- **title:** Precision Fabricators Ltd. — Hazardous Materials Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2018-03-30
- **effective on:** Not available
- **summary:** 17-0137 response to Precision Fabricators Ltd. concerning 173.301.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-17-0137.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-17-0137.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-17-0137
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/57856/170137.pdf
**body:**

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of Transportatior
J.S. Department
Washington, DC 20590
1200 New Jersey Avenue, SE
Pipeline and Hazardous
Administration
Materials Safety
MAR 3 0 2018
David Diamond
CEO
Precision Fabricators Ltd.
171 Tosca Drive
Stoughton, MA 02072
Reference No. 17-0137
Dear Mr. Diamond:
This letter is in response to your November 30, 2017, email requesting clarification of the
Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to cylinders.
Specifically, you ask whether a U.S. Department of Transportation (DOT) specification 4B
cylinder may be used to transport 500 cubic centimeters (0.5 liter) of anhydrous ammonia
mixture, of which half the cylinder will have anhydrous ammonia (liquid form) while the other
half will have ammonia gas (vapor form).
DOT 4B cylinders are not authorized for anhydrous ammonia. The Column 8B entry for
"UN1005, Anhydrous, ammonia" under the Hazardous Materials Table (HMT; § 172.101)
requires this material to be placed in a non-bulk cylinder prescribed in § 173.304. DOT 4B
cylinders are not included in the list of DOT cylinders authorized for use with anhydrous
ammonia in § 173.304a(a)(2). Furthermore, the Column 8A entry under the HMT specifies there
are no packaging exceptions for UN1005.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
7. Alans Foota
T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

<<<PAGE 2>>>

enman
173.301
January, Ikeya CTR (PHMSA)
Minders
From:
INFOCNTR (PHMSA)
17-0137
Sent:
Friday, December 15, 2017 2:09 PM
To:
Hazmat Interps
Subject:
FW: Request for interpretation
Importance:
High
Hello All,
Please see the below interp request.
Thanks!
-Breanna
From: David B. Diamond [mailto:DDiamond@precision-fab.com]
Sent: Thursday, November 30, 2017 5:37 PM
To: INFOCNTR (PHMSA) <INFOCNTR.INFOCNTR@dot.gov>
Subject: Request for interpretation
Importance: High
Dear PHMSA,
We are manufacturer M1114 making 316L stainless steel DOT4B cylinders and we have a customer seeking a cylinder to
transport ½ Liter (500cc) of anhydrous ammonia. However, only half of the cylinder will have anhydrous ammonia (in
liquid form) - the other half will have ammonia gas (ammonia in vapor phase). Maximum pressure will be 125psi. Due
to the anticipated volume, this link (https://www.fmcsa.dot.gov/faq/anhydrous-ammonia-covered-under-hazardous-
materials-safety-permit-program) suggests that this is not subject to the Hazardous Materials Safety Permit Program
We would like to determine if we may use a DOT4B300 cylinder for this application - we propose to fabricate a 4B 500cc
vessel with inlet and outlet ports both employing diaphragm valves. The cylinder will be pressure tested, helium leak
tested (under vacuum to 1x10-9 atm-cc/sec) and hydrostatic expansion tested as per 4B requirements. CFR 49 Section
173.301 specifically permits DOT4B vessels - see below:
§ 173.301 General requirements for shipment of compressed gases and
other hazardous materials in cylinders, UN pressure receptacles and spherical
pressure vessels.
(a)General qualifications for use of cylinders. Unless otherwise stated, as used in this section, the term
"cylinder" includes a UN pressure receptacle. As used in this subpart, filled or charged means an introduction or
transportation must meet the requirements in this section and §$ 173.301a through 173.305, as applicable.
presence of a hazardous material in a cylinder. A cylinder filled with a Class 2 hazardous material (gas) and offered for
metal cylinders and containers built in accordance with the DOT and ICC specifications and part 178 of this
(1) Compressed gases must be in UN pressure receptacles built in accordance with the UN standards or in
specifications authorized for use are as follows:
A table follows in CFR 49 173.301 which allows 4B cylinders.
1

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173.301 (pasted above - if interpreted in this fashion, a 500cc 4B cylinder would be allowed)
173.304a does not cite 4B cylinders for use with anhydrous ammonia (if interpreted directly, a 4B cylinder would not be
allowed)
173.306 makes an allowance for refillable containers below .95L in volume (if interpreted in this fashion, a 500cc 4B
cylinder would be allowed)
173.313 permits a UN pressure vessel (if interpreted in this fashion, a 500cc 4B cylinder would be allowed)
173.276 permits a heat treated vessel for anhydrous ammonia (if interpreted in this fashion, a heat treated 500cc 4B
cylinder would be allowed)
Precision Fabricators
171 Tosca Drive
Stoughton, MA 02072
Please welcome PFL's new Office Manager, Marisa Arai; marai@precisionfab.net, ext 201
Please welcome PFL's new Operations Leader, Shaun White; swhite@precisionfab.net, ext 234
David Diamond, CEO
+1.781.341.7242 x200 OFfice
TUV
SOD
wwww.precisionfab.net
ISO 9001
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