{"operation":"document","citation":"24-0081","title":"Infinite Composites, Inc. — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2025-01-13","effective_on":null,"summary":"24-0081 response to Infinite Composites, Inc. concerning 173.301.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-24-0081.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-24-0081.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-24-0081","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2025-01/240081.pdf","body":"<<>>\n\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\nJanuary 13, 2025\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nTravis Alley\nEngineering Manager\nInfinite Composites, Inc.\n10738 E. 55th Pl.\nTulsa, OK 74146\nReference No. 24-0081\nDear Mr. Alley:\nThis letter is in response to your September 4, 2024, email and subsequent conversations with\nmembers of our staff requesting clarification of the Hazardous Materials Regulations (HMR; 49\nCFR Parts 171-180) applicable to International Organization for Standardization (ISO) standards\nfor pressure vessels. Specifically, you ask whether an ISO pressure vessel is permitted to exceed\nits working pressure due to environmental conditions, and whether testing parameters can be\naltered to reflect the expected environmental conditions.\nWe have paraphrased and answered your questions as follows:\nQ1. You ask whether a pressure vessel designed and tested in accordance with the ISO 11119-\n3:2013 standard is permitted to exceed its working pressure when exposed to extreme\ntemperatures while held in storage after the pressure vessels are no longer in\ntransportation.\nA1. For the purposes of the HMR, the answer is yes as long as the pressure vessel is not in\nstorage incidental to transportation. The HMR apply to activities that involve the\ntransportation of hazardous materials, and the loading, unloading, or storage of hazardous\nmaterials incidental to transportation. Therefore, during transportation, § 173.301(a)(8)\nrequires that a cylinder’s internal pressure at 55 °C (131 °F) may not exceed 5/4 of the\nservice pressure of the cylinder and that the cylinder will not be liquid full at 55 °C (131\n°F). However, provided that the pressure vessel has been designed, filled, and maintained\nin accordance with the HMR, there is no requirement that prevents the pressure vessel\nfrom experiencing increased pressures due to fluctuating ambient temperature when that\npressure vessel has been placed in storage that is not incidental to a transportation.\nWe encourage you to look at other regulatory bodies for storage requirements such as the\nOccupational Safety and Health Administration, the U.S. Environmental Protection\nAgency, the Department of Defense, and state entities. We also encourage you to avoid\nsubjecting a pressure vessel to temperatures in excess of the design parameters.\n\n<<>>\n\nQ2. You ask whether the ambient cycle test in section 8.5.4.1 of the ISO 11119-3:2013\nstandard can be performed with a modified pmax calculation that reflects the expected\ntemperature of 75 °C rather than the prescribed temperature of 65 °C.\nA2. The answer is no. ISO specification pressure vessels must be constructed and tested in\naccordance with their respective Standard. In the case of the ISO 11119-3:2013 Standard,\nthe Ambient Cycle test in section 8.5.4.1 must be followed as written with the pmax\ncalculated based on a temperature of 65 °C.\nHowever, if you wish to deviate from the design qualification testing requirements you\nmay, in accordance with § 107.105, apply for a special permit to manufacture, mark, and\nsell a pressure vessel that is based on ISO 11119-3:2013, but for which pmax is measured at\n75 °C. Please note that a pressure vessel manufactured under a special permit would be\nmarked as a Department of Transportation Special Permit cylinder, not as an ISO\npressure vessel.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nSteven Andrews\nActing Chief, Regulatory Review and Reinvention Branch\nStandards and Rulemaking Division\n\n<<>>\n\nJacobson\n24-0081\nFrom: INFOCNTR (PHMSA)\nTo: Dodd, Alice (PHMSA)\nCc: Hazmat Interps\nSubject: FW: Request for Letter of Interpretation (ISO 11119-3:2013)\nDate: Friday, September 6, 2024 11:26:13 AM\nAttachments: PHMSA Request of Interpretation (9-4-24) .pdf\nHello Alice,\nPlease see the attached interpretation request. Let us know if you need anything.\nSincerely,\nJanaye\nFrom: Travis Alley \nSent: Wednesday, September 4, 2024 2:36 PM\nTo: PHMSA HM InfoCenter \nCc: Moore, Brian (PHMSA) ; Clark, Kenneth (PHMSA)\n; Branden Cattanach ; Michael\nTate ; Benjamin Roper ; Jared\nCuneo \nSubject: Request for Letter of Interpretation (ISO 11119-3:2013)\nCAUTION: This email originated from outside of the Department of Transportation (DOT). Do\nnot click on links or open attachments unless you recognize the sender and know the content\nis safe.\nGood Afternoon PHMSA Team,\nI am writing to request a letter of interpretation for ISO 11119-3:2013. I have attached a PDF, which\nincludes the specific questions we have. I am hoping to be able to provide a letter of support from\nthe Navy in the near future to hopefully expedite the process. Please let me know if you have any\nquestions, concerns, or further requirements/documentation to expedite this process.\nTravis Alley\nEngineering Manager\nInfinite Composites\n(918) 637-1043\nConfidentiality Notice: This email is intended only for the addressee named above. It contains\ninformation that is privileged, confidential or otherwise protected from use and disclosure. If you are\nnot the intended recipient, you are hereby notified that any review, disclosure, copying, or\n\n<<>>\n\ndissemination of this transmission, or taking of any action in reliance on its contents, or other use is\nstrictly prohibited. If you have received this transmission in error, please reply to the sender listed\nabove immediately and permanently delete this message from your inbox. Thank you for your\ncooperation.\n\n<<>>\n\nInfinite Composites, Inc.\n10738 E. 55th Pl.\nTulsa, OK 74146\n__________________________________________________________________________\nSeptember 4, 2024\nAttn: Mr. Shane Kelley\nDirector, Standards and Rulemaking Division\nU.S. DOT/PHMSA (PHH-10)\n1200 New Jersey Avenue, SE East Building, 2nd Floor\nWashington, DC 20590\nRE: Request of interpretation regarding ISO 11119-3.\nMr. Kelley,\nWe are designing a vessel containing Nitrogen with an intended working pressure of 8ksi and a maximum\ndeveloped pressure of 10ksi at 75c. This maximum developed pressure will be experienced exclusively during\nstorage of the bottle on hot days at an unconditioned facility.\nIn regards to the ISO 11119-3:2013 standard, there is no clear direction as to the acceptance/presence of\nMaximum Developed Pressure (Pmax). Section 8.5.4.1, ambient cycle test for a cylinder with dedicated gas,\nmakes provisions for testing to a pressure equal to Pmax at 65c, however does not advise as to whether or not\nthe vessel is permitted ever to exceed working pressure into this range during its lifetime.\nSeeing as ISO 11119-3 has recognized vessels may/will experience a pressure exceeding working pressure\nresulting from an increase in temperature and has made testing provisions for this, Infinite Composite’s\ninterpretation is that the bottle can be certified and stamped to a working pressure of 8ksi and permitted to\ndevelop a pressure not to exceed a pressure of Pmax during storage. This developed pressure would still have a\nsafety factor greater than 2.4. If the working pressure is increased to 10ksi, then the working pressure and\nevaluated Pmax would greatly exceed that of the actual expected conditions.\nFirst and foremost, ignoring the discrepancy in the temperature used to evaluate the maximum developed\npressure, if we qualify this bottle with a working pressure of 8ksi is it permissible for the vessel to develop a\npressure exceeding the working pressure to that of Pmax evaluated at 65c while in storage?\nSecondly, if the answer to the question above is yes, are we permitted to perform the ambient cycle testing\noutlined in 8.5.4.1 to a Pmax evaluated at 75c? If so we assume this falls under special permitting.\nIn consideration of this information please provide an official answer regarding the aforementioned interpretation\nof ISO 1111-3:2013.\nRegards,\nTravis Alley\nEngineering Manager\ninfinitecomposites.com 918-409-0384","truncated":false,"body_characters":8211}