# The Chlorine Institute — Hazardous Materials Safety Interpretation

- **operation:** document
- **citation:** 14-0229
- **title:** The Chlorine Institute — Hazardous Materials Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2015-04-16
- **effective on:** Not available
- **summary:** 14-0229 response to The Chlorine Institute concerning 179.100, 179.15.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-14-0229.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-14-0229.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-14-0229
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2015/140229.pdf
**body:**

<<<PAGE 1>>>

U.S. Department
of Transportation
Washington, DC 20590
1200 New Jersey Avenue SE
Pipeline and Hazardous
Administration
Materials Safety
APR 1 6 2015
Ms. Robyn Kinsley
Director, Transportation
The Chlorine Institute
1300 Wilson Blvd., Suite 525
Arlington, VA 22209
Reference No. 14-0229
Dear Ms. Kinsley:
This is in response to your November 18, 2014 letter requesting clarification of the
Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) relating to a tell-tale
indicator on a combination pressure relief device for a rail tank car. You ask if, in
accordance with HMR § 179.100-13(a) the outlet for a tell-tale indicator which has a
threaded outlet must be closed with an approved screw plug during transportation.
The requirement to close a tell-tale indicator having a threaded outlet with an approved
screw plug does apply. The requirements for pressure relief devices are found in HMR
§ 179.15. For a combination pressure relief system, § 179.15(e)(2) requires that a tell-tale
indicator be closed during transportation. The combination pressure relief system
designed with a tell-tale indicator must be in compliance with the AAR approved design
when utilizing a screw plug in the closed position.
I trust this information is helpful. If you have further questions, please do not hesitate to
contact this office.
Sincerely,
Duane A. Pfund
International Standards Coordinator
Standards and Rulemaking Division

<<<PAGE 2>>>

Babick
(79.156)(2)
Dodd, Alice (PHMSA)
129.100-13
From:
Sent:
Ciccarone, Michael CTR (PHMSA)
To:
Wednesday, November 19, 2014 1:43 PM
Pressin relif denices
Subject:
Hazmat Interps
Attachments:
FW: Requests for Interpretation
14-0229
2014-10-18 - PHMSA Interpretation Request - CL2 TC PRD Tell-Tale.pdf; 2014-10-18 -
PHMSA Interpretation Request - Package Securement.pdf
Shante/Alice,
Please submit these for formal letters of interpretation. Note that there are two separate requests attached.
Thanks,
Mike
From: Robyn Kinsley [mailto:rkinsley@CL2.com]
Sent: Wednesday, November 19, 2014 11:30 AM
To: PHMSA HM InfoCenter
Subject: Requests for Interpretation
you have any questions.
Please find attached two requests for interpretation from The Chlorine Institute. Please do not hesitate to contact me if
Regards,
Robyn Kinsley
www.chlorineinstitute.org
Robyn Kinsley | Director, Transportation | The Chlorine Institute | Arlington, VA | (703.894.4123 | rkinsley@CL2.com |

<<<PAGE 3>>>

THE CHLORINE INSTITUTE
THE CHLORINE INSTITUTE
1300 Wilson Blvd., Suite 525, Arlington, VA 22209
Tel 703-894-4140
Fax 703-894-4130
www.chlorineinstitute.org
November 18, 2014
Office of Hazardous Materials Standards
Pipeline and Hazardous Materials Safety Administration
ATTN: PHH-10
US Department of Transportation
East Building
1200 New Jersey Ave., SE
Washington, DC 20590
• RE: Request for Interpretation - Tell-Tale Indicator Securement on Pressure Relief Devices
The Chlorine Institute ('CI" or the "Institute") is a 193 member, not-for-profit trade association
of chlorine producers worldwide, as well as chlorine packagers, distributors, users, and
suppliers. The Institute's North American Producer members account for more than 93 percent
of the total chlorine production capacity of the U.S., Canada, and Mexico. Chlorine, a Division
2.3 toxic-by-inhalation hazardous (TIH) material, is used throughout the U.S. economy and is
key to the protection of public health.
Recently, a DOT site inspection at one of our members' facilities prompted some questions
related to combination pressure relief devices (PRDs) installed on chlorine tank cars.
Specifically, our question is with regard to the tell-tale indicator and how the requirements of
49 CFR 179.15(e)(2) and 179.100-13(a) are specifically applicable to the tell-tale indicator.
49 CFR 179.15(e) (2) states:
"...A device must be installed to detect any accumulation of pressure between the
rupture disc and the reclosing pressure relief valve. The detection device must be a
needle valve, trycock or tell-tale indicator. The detection device must be closed during
transportation." (emphasis added)
49 CFR 179.100-13(a) states:
"... Valve outlets shall be closed with approved screw plugs or other closures fastened
to prevent misplacement." (emphasis added)
It is clear to industry that all valves used for venting, loading, unloading, measuring or sampling
must be closed and all outlets should be closed with screw plugs or other closures for transport.
However, tell-tale indicators do not serve the same purpose as the service equipment
addressed by §179.100-13. Tell-tale indicators are typically very small needle valves, which may
or may not have a threaded outlet, that are used as leak detection features but are not directly

<<<PAGE 4>>>

CI Request for Interpretation - PRD Tell-Tale Requirements
November 18, 2014
Page 2 of 3
exposed to the product in the tank. The requirement addressed in §179.15(e)(2) only generally
notes that the device must be closed, and industry interprets this to mean that only the needle
valve must be closed. Therefore, our question is:
For those combination PRDs having a tell-tale indicator installed which has a threaded
outlet machined in the side, is the threaded outlet also required to be closed with a
screw plug during transportation?
It is understood that the primary closure of the tell-tale indicator must be closed for
transportation. Does that action alone achieve compliance with §179.15(e)(2)? Or must the
secondary threaded outlet on the tell-tale, if one exists, also be closed by means of a screw plug
or other closure? Please see the attached schematic for a sample of this type of tell-tale
indicator.
Our members are stewards of the safe handling of hazardous materials packages, and they
strive to achieve compliance with the hazardous materials transportation regulations. Further
clarification on this particular issue would greatly help that effort.
Thank you for your time on this matter.
Sincerely,
Restiney
Robyn Kinsley
Director, Transportation

<<<PAGE 5>>>

CI Request for Interpretation - PRD Tell-Tale Requirements
November 18, 2014
Page 3 of 3
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