The Chlorine Institute — Hazardous Materials Safety Interpretation

Page 1U.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 2Babick (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 3THE 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 4CI 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 5CI Request for Interpretation - PRD Tell-Tale Requirements November 18, 2014 Page 3 of 3 31) 4 5/8 DIA. REF. 15) 24 10 9/16 Tell-Tale Indicator - (closed 1/8" valve position) •1/8* NPT 1/8" (e3 outlet threaded 26) IN 6104A HAS 115055:203 30 OF CLDCATED AT CORNERS 6' SQUARE FLANGE). - 2.245- $.003 DIA#