{"operation":"document","citation":"21-0038","title":"Momentive Performance Materials — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2021-08-26","effective_on":null,"summary":"21-0038 response to Momentive Performance Materials concerning 173.315, 178.337, 180.407.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-21-0038.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-21-0038.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-21-0038","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/75786/210038.pdf","body":"<<<PAGE 1>>>\n\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nAugust 26, 2021\nMs. Kirsten Pink\nMomentive Performance Materials\n260 Hudson River Road\nWaterford, NY 12188\nReference No. 21-0038\nDear Ms. Pink:\nThis letter is in response to your April 9, 2021, email requesting clarification of the Hazardous\nMaterials Regulations (HMR; 49 CFR Parts 171-180) applicable to pressure relief devices for\nMC 331 cargo tanks. Specifically, you ask for clarification of the requirements for pressure\nrelief devices when a MC 331 cargo tank is used to transport “UN2988, Chlorosilanes, water-\nreactive, flammable, corrosive, n.o.s., 4.3, Packing Group (PG) I.\n”\nWe have paraphrased and answered your questions as follows:\nQ1. You ask whether § 178.337-9(a)(1)—which reads “See § 173.315(i) of this\nsubchapter.\n”\n—would apply to a MC 331 cargo tank transporting “UN2988,\nChlorosilanes, water-reactive, flammable, corrosive, n.o.s., 4.3, PG I.\n”\nA1. The answer is yes. Section 178.337-9 is part of the design specification requirements for\nMC 331 cargo tanks. Therefore, to be in compliance with the design specification\nrequirements for a MC 331 cargo tank, the requirements of § 178.337-9(a)(1) must be\nmet, which include the requirements of § 173.315(i).\nQ2. You ask what the set-to-discharge pressure is for a pressure relief valve installed in a MC\n331 cargo tank with a maximum allowable working pressure (MAWP) of 250 psi, and\nused in “UN2988, Chlorosilanes, water-reactive, flammable, corrosive, n.o.s., 4.3, PG I”\nservice.\nA2. As explained in PHMSA’s response to a previous request for Letter of Interpretation\n(LOI) 16-0090, § 173.315(i)(3) was amended in 2001 to add new requirements for UN\nportable tanks. In doing so, the term “tank” was modified to “portable tank, other than a\nUN portable tank,\n” thereby omitting cargo tanks from the specifications of the paragraph.\n\n<<<PAGE 2>>>\n\nHowever, pressure relief setting requirements for cargo tanks are found in § 180.407(j).\nSection 180.407(j)(1)(iv) specifies that pressure relief valves for MC 330 and MC 331\ncargo tanks must open at not less than the required set pressure and not more than 110%\nof the required set pressure. The valves must also reseat to a leak-tight condition at no\nless than 90% of the required set pressure. Therefore, the allowable start-to-discharge\npressure range for a pressure relief device installed in a MC 331 cargo tank with an\nMAWP of 250 psi is from 250 psi to 275 psi.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nT. Glenn Foster\nChief, Regulatory Review and Reinvention Branch\nStandards and Rulemaking Division\n\n<<<PAGE 3>>>\n\nWolcott\nFrom: INFOCNTR (PHMSA)\nTo: Hazmat Interps\nSubject: FW: Momentive - LOI 49CFR Part 178.337\nDate: Friday, April 9, 2021 4:35:32 PM\nAttachments: 2021-04-09_ Momentive_49 CFR Part 178 LOI.docx\n21-0038\nHello Alice,\nAttached is a request for letter of interpretation.\nThanks,\nJonathon, HMIC\nFrom: Pink, Kirsten [mailto:kirsten.pink@momentive.com]\nSent: Friday, April 9, 2021 3:25 PM\nTo: INFOCNTR (PHMSA) <INFOCNTR.INFOCNTR@dot.gov>\nSubject: Momentive - LOI 49CFR Part 178.337\nCAUTION: This email originated from outside of the Department of Transportation (DOT). Do not click on links or\nopen attachments unless you recognize the sender and know the content is safe.\nDear Sir or Madam,\nPlease find the attached request for regulatory clarification.\nPlease fee free to contact me should you require any additional information.\nBest Regards,\nKirsten Pink\nAMR Supply Chain Regulatory Leader\nMomentive\nKirsten.pink@momentive.com\n(m) 518-441-8998\nThis message, including attached files, is confidential and intended for the addressees. It may contain information that is proprietary, privileged or\nexempt for disclosure under applicable law. Any unauthorized use and dissemination of the information or copying of this message is strictly\nprohibited. Any views, opinions or conclusions expressed in this message are those of the individual sender and do not necessarily reflect the views of\nMomentive or its affiliates. If you received this message in error, please immediately advise the sender by reply email, delete all copies of this message\nand refrain from printing, copying, or disseminating this message or otherwise using the information in it. Thank you.\nAlthough Momentive routinely screens incoming and outgoing mail messages for viruses, addressees should scan this e-mail and any attachments for\nviruses themselves. Momentive does not guarantee in any way the absence of viruses in this e-mail or any attachments and disclaims any liability in\ncase of security problem that this message may cause to any system.\n\n<<<PAGE 4>>>\n\nWolcott\nMomentive Performance Materials Inc.\n260 Hudson River Road\nWaterford, NY 12188\nmomentive.com\n21-0038\nApril 9, 2021\nAssociate Administrator for Hazardous Materials Safety\nPipeline and Hazardous Materials Safety Administration\nUS Department of Transportation, East Building\n1200 New Jersey Avenue SE\nWashington, DC 20590–0001\nAttn: Standards and Rulemaking [PHH-10)\nSubject: Request for interpretation 49 CFR Part 178.337-9 and 173.315\nDear Sir or Madam:\nWe request clarification (via a letter of interpretation) relating to the pressure relief valve setpoint\nfor a MC 331 cargo tank. It is our understanding that 49 CFR Part 178.337-9 is the regulation\nthat addresses this requirement for a MC 331 cargo tank, however we are uncertain if 49 CFR\nPart 173.315 is also applicable.\nFor this specific case, the MC 331 is utilized for chlorosilane transport, specifically UN 2988\nChlorosilanes, water-reactive, flammable, corrosive.\nBased upon our review of the regulation 49 CFR Part 178.337-9(3), for a MC 331 in the above\nservice, the pressure relief valve for this tank “must be designed, constructed, and marked for a\nrated pressure not less than the cargo tank design pressure at the temperature expected to be\nencountered”. It is unclear however as to whether 49 CFR Part 178.337-9(a) would apply for a\nMC 331 in this service. This regulation references 49 CFR Part 178.315(i).\nWe would appreciate guidance for what the acceptable relief valve setpoint would be for a MC\n331, with a MAWP of 250 psi, in this chlorosilane service.\nPlease feel free to contact me if you have any questions or need clarification to respond to this\ninquiry.\nBest Regards,\nKirsten Pink\nKirsten Pink\nAMR Supply Chain Regulatory Leader\nMomentive Performance Materials\n260 Hudson River Rd\nWaterford, NY 12188\nKirsten.pink@momentive.com\n(m) 518-441-8998","truncated":false,"body_characters":6630}