{"operation":"document","citation":"10-0077","title":"Thunderbird Cylinder — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2011-09-14","effective_on":null,"summary":"10-0077 response to Thunderbird Cylinder concerning 173.301, 180.209.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-10-0077.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-10-0077.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-10-0077","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretations/2010/100077.pdf","body":"<<<PAGE 1>>>\n\n1200 New Jersey Avenue SE\nU.S. Department Washington. DC 20590\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\nSFP 14 2011\nMr. Fred A. Nachman\nPresident\nThunderbird Cylinder\n4209 E. University Drive\nPhoenix, AZ 85034-7315\nRef. No.: 10-0077\n. Dear Mr. Nachman:\nThis responds to your letter requesting clarification ofthe requirements concerning the tare\nweight of liquefied petroleum gas (LPG) cylinders under the Hazardous Materials Regulations\n(HMR; 49 CFR Parts 171-180).\nQ1. Does a low pressure (LPG) cylinder being visually inspected need to have its\nvalve/PRD removed to verifY there is no liquid inside it that would result in improper\ntare weight verification?\nA1. No. A cylinder confonning to §180.209 used exclusively in LPG service may be\ngiven an external visual inspection in lieu ofa hydrostatic test. No measurement of\nthe tare weight is required for the external visual inspection. When the cylinder\nexhibits corrosion, the cylinder must be further examined for condemnation. The\ncylinder must be examined by measuring tare weight in accordance with CGA C-6,\n5.2.1.1 (1). The cylinder must be empty. The tare weight is measured with the valve!\nPRD connected. Cylinders exempt from tare weight measurement must be examined\nby measuring wall thickness in accordance with CGA C-6, 5.2.1.1 (2), (3), or (4).\nQ2. At the time ofrequalification, should the pressure relief device (PRD) be changed?\nA2. No. There is no regulatory requirement to change the PRD at the time of\nrequalification. Pressure relief devices must be tested for leaks before a filled cylinder\nis shipped in accordance with §173.301(a)(2) and (3).\nQ3. Should it even be an option to hydrostatically test or steam clean LPG cylinders when\nethyl mercaptan exposed to water/moisture is corrosive?\n\n<<<PAGE 2>>>\n\nA3. Cylinders containing LPG in accordance with § 180.209(g) may be given an external\nvisual inspection in lieu of a hydrostatic pressure test. This would avoid adding\nmoisture to the cylinder. If steam cleaning is used, it is the responsibility ofthe filler\nto make sure the cylinder is dry before filling with a hazardous material, if moisture is\ndangerous to the cylinder (§173.301(d».\nI hope this information is helpful. Ifwe can be of further assistance, please contact us.\nSincerely,\n~S;~\nBen Supko\nChief, Standards Development Branch\nStandards and Rulemaking Division\n\n<<<PAGE 3>>>\n\nDate: April 1 , 2010\nTo: Hattie.mitchell@dot.gov\nMark. toughity@dot.gov\nRyan.posten@dot.gov\nSubj: Request for clarification concerning tare weights of propane/LPG cylinders\nQuestion No.1. Does a low pressure propane (LPG) cylinder being visually inspected need\nto have its valve/PRD removed to verify there is no liquid inside it that would result in\nimproper tare weight verification? 0 Yes 0 No '\nReference is made to 49CFR180.209(g) Visual inspections A cylinder (DOT 3A, 3AA, 3B, 4B,\n4BA, 4BW rylinders in liquefiedpetroleum gas) ... used exclusively in the service indicated may, instead of\na periodic hydrostatic test, be given a complete exterior visual inspection ... in accordance with CGA\nPamphlet C-6 ...\nCGA C-6-2007-5 Low pressure cylinders exempt from hydrostatic testin~-5.2.1.1 Corro~ c..~\nlimits When a cylinder exhibits corrosion, the cylinder shall be condemned when the tare weight is\nless than 90% of the original stamped tare weight. .. When determining tare weight, be sure the\ncylinder is emp!Jl. Cylinders that are used exclusively in noncorrosive gas service and meet one or\nmore of the conditions below are exempt from tare weight checking requirement: ...\nWhy would propane cylinders be exempted from tare weight verification when (1) that cylinder\ncoming in for requalification after 12 years in its original service cycle and exposed to the elements\nwill undoubtedly exhibit some amount of external corrosion, (2) the original stamped mfr tare weights\nwere not necessarily correct, (3) the valve/PRD may have been changed out with one(s) of different\nweights, (4) it is unclear how much liquid remains in the cylinder effecting the weight, or (5) the\ncylinder contains the proper length dip tube on its spitter?\nQuestion No.2. At time ofrequalification, should the PRO be changed? 0 Yes 0 No\nIt is our understanding that these resettable PRD's will reset at lower and lower PSI's as they\ncontinue to relieve pressures and reset over years in service.\nQuestion No.3. Should it even be an option to hydrostatically test or steam clean LPG\ncylinders when ethyl mercapin exposed to water/moisture is corrosive? 0 Yes 0 No\n~llY submitted,\n·~O~O(~\nFred A. Nachman\nPresident\n(Propane_ VisuaUnspection_C1arification_ 411O.doc)\n4209 E. University Drive· Phoenix, AZ • 85034-7315\nPHONE: 602.437.4600 • FAX: 602.437.5052 • EMAIL: fredn@cylinder.com","truncated":false,"body_characters":4784}