{"operation":"document","citation":"20-0057","title":"R&D Engineer — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2020-10-13","effective_on":null,"summary":"20-0057 response to R&D Engineer concerning 173.301, 178.71.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-20-0057.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-20-0057.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-20-0057","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/74496/200057.pdf","body":"<<<PAGE 1>>>\n\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nOctober 13, 2020\nOliver Sánchez Muñoz\nR&D Engineer\nJohnson Controls\nJosep Ros i ros, Naves 23. P.I. La Clota.\n08740 Sant Andreu de la Barca, Spain\nReference No. 20-0057\nDear Mr. Muñoz:\nThis letter is in response to your August 4, 2020, email requesting clarification of the Hazardous\nMaterials Regulations (HMR; 49 CFR Parts 171-180) applicable to service equipment for United\nNations (UN) cylinders as it relates to certain ISO standards. You state you have a UN cylinder\nfilled with a liquid extinguishing agent charged with a compressed gas, and the cylinder is\nequipped with pressure gauges and switches mounted to a quick release valve. Furthermore, you\nreference ISO 17871:2015, incorporated by reference in § 173.301b(c), and you indicate your\nunderstanding that section 4.2.6 of this standard provides additional requirements to those in ISO\n10297:2014 as it relates to specification standards for service equipment under § 178.71(d). You\nalso note that a recent update to ISO 17871 (2020) indicates that the valve burst test pressure is\nto be calculated at 1.5 times the valve test pressure, which is consistent with the same\nrequirement for liquefied gases in ISO 10297:2014. Finally, you note your understanding that\nthe instruction in section 4.2.6 of ISO 17871:2015 is that the valve test pressure must be at least\nthe developed pressure of a full gas cylinder at 65 °C and will never exceed the test pressure of\nthe pressure receptacle (i.e., the UN cylinder).\nYou ask whether pressure gauges and switches mounted to quick release valves covered under\nISO 17871:2015 comply with the hydraulic burst pressure test requirement when successfully\ntested (e.g., no visible deformation or burst) at 1.5 times the developed pressure of a full gas\ncylinder at 65 °C regardless of the test pressure marked on the cylinder.\nThe answer to your question is no. The pressure gauge and switches mounted to the quick\nrelease valve must meet the burst test requirement of the cylinder that is being used.\nFurthermore, for purposes of performing the hydraulic burst pressure test in ISO 10297:2014, the\nformula you describe is used to determine the value of the burst test pressure. However, for\npurposes of § 178.71(d)(1), UN pressure receptacle equipment (e.g., a quick release valve) that is\nsubjected to pressure must be designed and constructed to withstand at least 1.5 times the test\npressure of the pressure receptacle. Therefore, if the calculated valve burst test pressure is less\n\n<<<PAGE 2>>>\n\nthan 1.5 times the marked cylinder test pressure, the performance standard of § 178.71(d)(1)\nwould not be achieved. Please also note that for purposes of ISO 10297:2014, section 6.3, valves\ndesigned to incorporate pressure gauges or pressure indicators must have the devices installed for\ntesting, except for the hydraulic burst pressure test.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nDirk Der Kinderen\nChief, Standards Development Branch\nStandards and Rulemaking Division\n\n<<<PAGE 3>>>\n\nBaker\n20-0057\nFrom: Oliver Sanchez Muñoz\nTo: INFOCNTR (PHMSA); Baker, Yul (PHMSA)\nCc: Dodd, Alice (PHMSA); Carlos Perez Perez\nSubject: 20-0029\nDate: Tuesday, August 4, 2020 9:28:13 AM\nAttachments: 20-0029 Letterhead.pdf\nImportance: High\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 Yul, Dear Sirs,\nWe have received the attached letter of interpretation. Going little deeper on the details of that\nletter, we came to the following exposed approach. Please see below explanation and additional\nquestion we would like you to answer.\nThanks.\nYour letter reference No 20-0029 in response to our letter dated April 1, 2020, are referring to final\nrule HM-215O published by PHMSA where ISO10297:2014 is incorporated by reference. It should be\nnoted that also ISO17871:2015 has also been incorporated by the mentioned final rule.\nThe application we are looking at is liquid extinguishing agents charged with compressed gases and\npressure gauges and pressure switches that are mounted on valves covered by ISO17871 (quick\nrelease valves).\nISO17871:2015, 4.2.6 introduces additional requirements to ISO10297:2014, 6.6.2. According to this\nadditional requirements Pvt (valve test pressure) is determined as the developed pressure of a full gas\ncylinder at 65ºC and this pressure shall never exceed the test pressure of the pressure receptacle.\nPvbt is typically calculated as 1.5 times Pvt. So in these cases the reference to the test pressure\nmarked on the cylinder may not be applicable.\nNOTE: ISO17871:2020 4.2.7 (recently published), though not included of HM215O, fills a potential\ngap on how Pvbt is to be calculated, establishing that Pvbt for extinguishing agents charged with\ncompressed gases is to be calculated as 1.5 time Pvt as for liquefied gases.\nNOTE: The developed pressure of a full gas cylinder at 65ºC shall never exceed the test pressure of\nthe pressure receptacle.\nSo, taken the above into consideration and given that now ISO10297:2014 and ISO17871:2015 have\nbeen incorporated by reference and restricting the scope of the question number 1 that was originally\nposed to this specific case, we ask the following:\nQUESTION:\n\n<<<PAGE 4>>>\n\nFor liquid extinguishing agents charged with compressed gases, do pressure gauges and pressure\nswitches mounted on valves covered by ISO17871:2015 as service equipment for UN cylinders comply\nthe hydraulic burst pressure test requirement when successfully tested (no visible deformation or\nburst) at 1.5 times the developed pressure of a full gas cylinder at 65ºC, regardless of the test\npressure marked in the cylinder.\nBest regards / Atentamente,\nOliver Sánchez Muñoz\nR&D Engineer\nJohnson Controls\n+34 673838438 direct\noliver.sanchez.munoz@jci.com\n@johnsoncontrols.com\nwww.johnsoncontrols.com\nJohnson Controls\nJosep Ros i ros, Naves 23. P.I. La Clota.\n08740 Sant Andreu de la Barca\nSpain\nTHIS MESSAGE MAY CONTAIN INFORMATION THAT IS PRIVILEGED AND CONFIDENTIAL. The information contained in,\nor attached\nto, this message is intended solely for the use of the specific person(s) named above. If you are not the intended recipient then you have\nreceived this communication in error and are prohibited from review, retransmission, taking any action in reliance upon, sharing the\ncontent of, disseminating or copying this message and any of the attachments in any way. If you have received this communication in\nerror, please contact the sender immediately and promptly delete this message from all types of media and devices. Thank you.","truncated":false,"body_characters":6837}