{"operation":"document","citation":"03-0159","title":"Airgas, Inc. — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2003-11-05","effective_on":null,"summary":"03-0159 response to Airgas, Inc. concerning 173.302.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-03-0159.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-03-0159.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-03-0159","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2003/030159.pdf","body":"<<<PAGE 1>>>\n\nU.S. Department\nof Transportation\nResearch and\nNOV - 5 2003\n400 Seventh St., S.W.\nWashington, D.C. 20590\nAdministration\nSpacidi Programs\nMr. John Anderson\nDirector of DOT Operations\nRef No: 03-0159\nAirgas, Inc.\nP.O. Box 20067\nCheyenne, WY 82003\nDear Mr. Anderson:\nThis is in response to your telephone conversation with Sandra Webb of this office and\nsubsequent letter, requesting a clarification of the requirements for filling DOT specification\nRegulations (HMR; 49 CFR Parts 171-180).\ncylinders with non-liquefied (permanent) compressed gases under the Hazardous Materials\nYou stated that it is industry practice to add approximately 50 psi to 100 psi to the target fill\npressure so that, once the cylinder has cooled, the pressure in the cylinder at 70 °F. will be as\ncylinder, such as a DOT 3A, 3AA or 3AL cylinder, may be filled in excess of its marked service\nclose as possible to its marked service pressure. Specifically, you ask whether a high-pressure\npressure.\nA cylinder may be filled to a pressure in excess of the marked service pressure to compehsate for\ncertain factors, such as heat of compression, high ambient temperature or changes in elevation.\ncylinder at 21 °C. (70 °F.) must not exceed the service pressure for which the cylinder is marked\nHowever, § 173.301a(c) specifically states that when offered for transportation, the pressure in a\nor designated, except as provided in § 173.302a(b) of the HMR. This requirement has been in\nindustry.\neffect for many years, and it is based on standards and recommendations of the compressed gas\nIn your letter, you imply there is an inconsistency between fill limit requirements of the HMR\n(FDA). We disagree. FDA concurs with RSPA that the internal pressure at 21 °C.\nand those of the U.S. Department of Health and Human Services' Food and Drug Administration\n(70 °F.) must not exceed the cylinder's service pressure. Therefore, your operating procedures\nmust ensure that the marked service pressure is not exceeded when the cylinder is offered for\ntransportation.\nI hope this information is helpful. If we can be of further assistance, feel free to contact us.\nSincerely,\nSalual 7. Mazzallo\nEdward T. Mazzullo\nDirector, Office of Hazardous\nMaterials Standards\n113.302\nTELLINE HIMANI\n030159\n\n<<<PAGE 2>>>\n\nAirgas.\nDirector of DOT Operations\nJohn Anderson\nAirgas, Inc.\nCheyenno, WY 82003\nPO Box 20067\nhttp://www.airgas.com\n(307) 778-8809 Fax: (307) 778-7497\njohn.anderson@airgas.com\nJune 25, 2003\nSandra Webb\nDOT/RSPA\n400 Seventh St. SW\nWashington, DC 20590\nDear Ms. Webb:\nPer our conversation today, please provide Airgas with guidance on how to comply with\nthe following.\nThe compressed gas industry fills high-pressure cylinders (such as 3A, 3AA and 3AL)\nallow for the filling of these cylinders at different pressures and temperatures to obtain\nby pressure and temperature, per 49 CFR 173.301a. Charts have been developed that\nthe correct service pressure/product.content.\nThe gauges and thermometers that are used are calibrated, but the manufacturer of the\ngauge states the gauge is accurate to 1.5%, and the thermometer is accurate to 0.5%.\nEven when working within this range, it is almost impossible to obtain a 100% accurate\nservice pressure. A 2% variance on a cylinder rated at 2,015 psi is a 40-psi difference.\nAs a cylinder is being filled, the temperature of the compressed gas raises the\ntemperature of the cylinder. The compressed gas inside the cylinder is getting hotter\n(due to compression), and it takes a while for the increased heat to penetrate the wall of\nthe cylinder. It is difficult to obtain a 100% accurate temperature reading on the outside\ncylinder wall.\nThe filling process becomes more difficult because the DOT states the cylinder cannot\nbe over-filled, and the FDA states the cylinder cannot be under-filled. The FDA requires\nthat the cylinder have the correct amount of product since the product is dispensed as a\nmedical gas.\nThe industry practice is to add approximately 50 to 100 psi to the target fill pressure so\nthat once the cylinder is allowed to cool to the room temperature, the cylinder will be as\nclose as possible to the correct service pressure when the settle pressure check is\nperformed. As you know, the DOT removed the requirement to perform a settle\npressure check (on high pressure cylinders), and the requirement to maintain a settle\npressure log (on high pressure cylinders) in the October 1, 2002 update to 49 CFR.\nRecently, Christopher Michalski, an inspector from the RSPA office in NJ performed an\naudit at one of our locations. Mr. Michalski reviewed our FDA cylinder filling records.\nHe noted that our FDA cylinder filling record recorded a settle pressure in excess of the\ncylinders service pressure. Example, if the cylinder was a 3AA 2015, the cylinder might\nhave a settle pressure of 2,055 psi at 70 degrees.\n\n<<<PAGE 3>>>\n\nMr. Michalski noted on the exit briefing, \"173.302 & 173.301(c) Shipping oxygen,\nunauthorized package\".\ncompressed, 2.2, UN 1072 in a cylinder filled above the service pressure, therefore\nAs noted above, we follow the standard industry practice that has been used safely for\nam improve our in or are and please provide Are and dancer me\nalmost 100 years.\nfilling high-pressure cylinders.\nJohn Anderson\nDirector of DOT Operations\nAirgas, Inc.","truncated":false,"body_characters":5313}