Truck Trailer Manufacturers Association — Hazardous Materials Safety Interpretation

Page 1INTERPRETATION LETTERS Requester John Freiler Date Received: 10/9/2018 Company Truck Trailer Manufacturers Association Tracking 18-0125 Phone 703-549-3010 Revision Date: 10/9/2018 Date Assigned 10/09/2018 Date of Letter 10/05/2018 Staff Wolcott First Draft Due: 10/30/2018 Section I First Draft Date Subject Concurrence Status PHH-10-Specialist Status Date 10/9/2018 Sign Date Signor Comment HBP Copy to Docket Copy to DHM-60#

Page 2January, Ikeya CTR (PHMSA) From: Foster, Glenn (PHMSA) Sent: Tuesday, October 09, 2018 1:23 PM To: Dodd, Alice (PHMSA); January, Ikeya CTR (PHMSA) Subject: Fwd: Request for Interpretation - MC-331 Shear Sections Attachments: TTMA Request for Interpretation - MC331 Shear Sections.pdf Incoming Interp. T. Glenn Foster Chief, Regulatory Review and Reinvention Standards and Rulemaking Division Office of Hazardous Materials Safety Pipeline and Hazardous Materials Safety Administration U.S. Department of Transportation 1200 New Jersey Avenue, S.E. Washington, DC 20590 202-366-4453 glenn.foster@dot.gov From: John Freiler <john@trucktrailer.org> Sent: Friday, October 5, 2018 2:21:42 PM To: PHMSA HM InfoCenter Cc: PHMSA Petitions; Carrie Renuart; Jeff Sims Subject: Request for Interpretation - MC-331 Shear Sections Please see the attached request for Interpretation regarding shear sections on MC-331 cargo tanks. Thanks! John Freiler - Engineering Manager TTMA TRUCK TRAILER Manufactured Truck Trailer Manufacturers Association TruckTrailer.org Since 1941 7001 Heritage Village Plaza Suite 220 Gainesville, VA 20155-3094 703-549-3010 - Phone 1#

Page 3TTMA RICK TRAILER Manufacturer Tank Conference TTMAnet.org Since 1941 Associatio Jeffrey M. Sims • President 7001 Heritage Village Plaza • Suite 220 • Gainesville, VA 20155 • 703-549-3010 October 5, 2018 U.S.DOT PHMSA-Office of Hazardous Materials Standards Attn: PHH-10 East Building 1200 New Jersey Ave, SE Washington, DC 20590 Phmsa.hm-infocenter@dot.gov Subject: Request for Interpretation - MC331 Shear Sections Dear Sirs, We are requesting formal interpretation of the HMR requirements for shear sections on valves installed on MC-331 Cargo tanks. 49CFR 178.337-10(f) requires a shear section for valves specified in subparagraphs (1) and (2) of paragraph (f). These valves are typically located on the bottom exterior of the tank, and the accident damage protection in 178.337-10 is also typically located on the bottom exterior of the tank. Does 49CFR 178.337-10(f) apply to valves located within a recessed well that meets accident damage protection requirements on top of an MC-331 Cargo Tank? May a ball valve without a shear section be used for liquid and vapor connections within a recessed well on top of an MC-331 Cargo Tank provided all other requirements are met? If you have any questions at all, please feel free to contact me. Sincerely, John Freiler John Freiler Engineering Manager Cc PHMSAPetions@dot.gov#

Page 4of Transportation U.S. Department 1200 New Jersey Avenue, SE Washington, DC 20590 Materials Safety Pipeline and Hazardous Administration APR 1.6 2019 John Freiler Truck Trailer Manufacturers Association 7001 Heritage Village Plaza, Suite 220 Gainesville, VA 20155 Reference No. 18-0125 Dear Mr. Freiler: This letter is in response to your October 5, 2018, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the design of MC-331 cargo tanks. Specifically, you ask about the requirements for shear sections on valves. We have paraphrased and answered your questions as follows: Q1. You ask if § 178.337-10(f) applies to valves located within a recessed well that meet the accident damage protection requirements on top of an MC-331 cargo tank. Al. The answer is yes. Section 178.337-10(f) still applies to valves located on the top of an MC-331 cargo tank that meet the requirements for accident damage protection. Q2. You ask if a ball valve without a shear section may be used for liquid and vapor connections within a recessed well on top of an MC-331 cargo tank. A2. The answer is no. A shear section is still required. The ball valve and recessed well do not except the cargo tank from the requirements for shear sections on valves. I hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, tern Poster T. Glenn Foster Chief, Regulatory Review and Reinvention Standards and Rulemaking Division#