{"operation":"document","citation":"10-0079","title":"Air Liquide Industrial U.S. LP — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2010-05-31","effective_on":null,"summary":"10-0079 response to Air Liquide Industrial U.S. LP concerning 173.320.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-10-0079.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-10-0079.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-10-0079","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretations/2010/100079.pdf","body":"<<<PAGE 1>>>\n\nU.S. Department of Transportation 1200 New Jersey Ave. SE\nWashington, D.C. 20590\nPipeline and Hazardous Materials\nSafety Administration\nMAY 26 2010\nMr. Steven Bilger\nAir Liquide Industrial U. S. LP\n12800 West Little York Road\nHouston, TX 77041\nRef. No. 10-0079\nDear Ms. Bilger:\nThis responds to your April 9, 2010 email requesting clarification of the Hazardous Materials\nRegulations (HMR; 49 CFR Parts 171-180) regarding a nitrogen, refrigerated liquid based\nrefrigeration system designed for insulated transport trailers. Specifically you ask if the HMR\napply to the 250 gallon cryogenic tank mounted to the bottom of a refrigerated trailer that is\nused to feed one or more heat exchangers within the trailer.\nThe answer is no. Section 173.320(b)(2) provides an exception for atmospheric gases when\nused in operation of a process system; such as a refrigeration system.\nI hope this answers your inquiry. If you have further questions, please do not hesitate to contact\nthis office.\nSince:~~\naries E. Betts\nC . ef, Standards Development\nOf 1 of Hazardous Materials Standards\n\n<<<PAGE 2>>>\n\nDrakeford, Carolyn (PHMSA)\nFrom: INFOCNTR (PHMSA) 10 10074\nSent: Friday, April 09, 20104:07 PM\nTo: Drakeford, Carolyn (PHMSA)\nSubject: FW: Hazmat Information Center Feedback: Interpretations (Letters) Issued by PHMSA\nCarolyn,\nAttached is yet another written request for an interpretation.\nThanks,\nRob\n-----Original Message----From:\nPHMSA-Feedback [mailto:PHMSA-Feedback]\nSent: Friday, April 09, 2010 3:44 PM\nTo: PHMSA HM InfoCenter; PHMSA Webmaster\nSubject: Hazmat Information Center Feedback: Interpretations (Letters) Issued by PHMSA\nI would like to request a written letter of interpretation concerning the applicability of 49\nCFR 173.320(b)(2) to a liquid nitrogen-based refrigeration system designed for insulated\ntransport trailers. The refrigeration system consists of an insulated 250 gal cryogenic tank\nmounted to the bottom of the trailer which feeds one or more heat exchangers within the\ntrailer. The flow of liquid nitrogen, the refrigerant, from the tank to the heat exhangers\nis due to tank pressure alone and is controlled by a network of valves, which either allow or\nprevent nitrogen flow. The transfer of heat from the trailer to the nitrogen causes the\nnitrogen to boil and vaporize within the heat exchanger coils. The heat exchanger coils feed\na vent line which is piped outside of the trailer so as to avoid any nitrogen gas build up\nwithin the trailer. For the process to run effectively, a pressure of 30-60 psig is required\nwithin the liquid nitrogen tank during transport.\nName: Stephen Bilger\nOrganization: Air Liquide Industrial U.S. LP\nEmail: stephen.bilger@airliquide.com\nAddress: 12800 West Little York Road\nCity: Houston\nZip Code: 77041\nPhone: 713-896-2247\nFAX: 713-896-2390\n1","truncated":false,"body_characters":2814}