{"operation":"document","citation":"00-0117","title":"Aerostatic Engineering — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2002-04-24","effective_on":null,"summary":"00-0117 response to Aerostatic Engineering concerning 173.29.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-00-0117.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-00-0117.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-00-0117","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2000/000117.pdf","body":"<<<PAGE 1>>>\n\nJ.S. Department\nof Transportation\n400 Seventh St., S.W.\nWashington, D.C. 20590\nResearch and\nspecial Programs\nAdministratior\nAPR 24 2002\nMr. John Terry\nReference No. 00-0117\nAcrostatic Engineering\n495 East Brokaw Road\nSan Jose, CA 95112\nDear Mr. Terry:\nThis is in response to your letter concerning the purging of a propane cylinder that will be\noffered for transportation by aircraft under the Hazardous Materials Regulations (HMR; 49 CFR\nParts 171-180). You enclosed materials on outline your procedures for purging cylinder to a\npoint where the fuel to air ratio is below 2 percent. You inquired how far under 2 percent is\n. purging required. We apologize for the delay. in responding and regret any inconvenience it may\nhave caused.\nAs you state, § 173.29(b)(2)(ii) requires that a cylinder be sufficiently cleaned of residue and\npurged of vapor to remove any potential hazard to be considered as not regulated under the\nHIMR. The methods and limits used for determining what qualifies as a \"cleaned and purged\"\nunder the HMR are intentionally not defined because they vary greatly depending on the\nproperties of the particular hazardous material and type of packaging. In the case of propane,\nother variables such as purge medium, temperature conditions and cylinder volume are also\nfactors. We would consider a propane cylinder to be sufficiently cleaned and purged when the\nvapors in the cylinder are no longer capable of sustaining combustion. Of course, when a\ncleaned and purged cylinder is offered for transportation by aircraft, the cylinder valve must be\nleft open to preclude internal pressure buildup, as prescribed in packing instruction 200 of the\nInternational Civil Aviation Organization's Technical Instructions for the Safe Transport of\nDangerous Goods by Air.\nI hope this satisfies your request.\nSincerely,\nHothe 2. mith el\nHattie L. Mitchell, Chief\nRegulatory Review and Reinvention\nOffice of Hazardous Materials Standards\n•\n173,29\n000117\n\n<<<PAGE 2>>>\n\nFROM :\nPHONE NO. : 408 8676390\nMay. 07 2002 02:37PM P2\nU.S. Department of Transportation\nResearch and Special Programs Administration\nOffice of Hazardous Material Standards DHM-10\nWashington DC. 20590\n400 7th. St. SW\nDear Mr. Edward Mazzuilo\nI operate an FAA certified hot air balloon repair station (T4YR452N) in San Jose, California. A:\nshipment.\nane of the services provided by the repair station, I prepare hot air balloon systems for ai\nI have had a number of customers comment on trouble they have had with recent air shipments.\nand ICAO rules require the tanks be empty and purged with the service valves open.\nHot air balloons have propane fuel tanks, usually four tanks of 10 to 18 gallon capacity. FAA\nNO ONE HAS BEEN ABLE TO TELL ME HOW FAR UNDER 2% I NEED TO PURGE FOR AIR\nSHIPMENT. I have conducted a number of tests with various purging methods and variou\npercent fuel/air ratio. (Data attached)\nurging gases. The resultant data defines how much purging is required to reach a desires\nI have read your \"Interpretation Letter\" on tank purging and found it totally inadequate. There\nare no specific numbers for propane purging, therefore a person doing the purging has no idea if\nhe has met the requirements.\nCould you please provide a more definitive \"Interpretation Letter\" that defines a \"safe\" purged\nThank you for your help in this matter.\nSincerely,\nLe Te\nTerr\n495 E. Brokaw Rd.\nSan Jose, CA 95112\nKathleen Roscher, Lead Special Agent","truncated":false,"body_characters":3442}