# National Propane Gas Association — Hazardous Materials Safety Interpretation **Citation:** 98-0604 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 1998-10-05 98-0604 response to National Propane Gas Association concerning 180.407. ## Document text <<>> : • Laven 180.V01 file. SC. 33%, NPGA National PROPANE GAS Association 4301 North Fairfax Drive, Suite 340 - Arlington, Virginia 22203 • 703/351-7500 • Fax 703/351-7505 March 20, 1996 File: 285.07.11 Mr. Edward Mazzullo Office of Hazardous Materials Safety Research & Special Programs Administration • U.S. Department of Transportation J 400 Seventh St., S. W Washington, D.C. 20590-0001 Dear Mr. Mazzullo: A member company has approached us with a problem they have encountered in several mid-western these states have reportedly issued citations for violation of the annual leakage test requirements for states with entorcement of the Hazardous Materials Regulation (HIMR). Field inspectors in each of cargo tanks ($180.407) in the DOT Hazardous Materials Regulations. Because of the widespread importance of such an interpretation, the company has asked the NPGA to obtain a formal interpretation of the provision in question. NPGA is the national trade association of the LP-gas (principally propane) industry with a membership of about 3,500 companies, including 37 affiliated state and regional associations, members in all 50 states. Although the single largest group of NPGA members are retail marketers of propane gas, the membership. also includes propane producers, transporters and wholesalers, as well as manufacturers and distributors of associated equipment, containers and appliances. Propane in agriculture, in industrial processing, and as a clean air alternative engine fuel for both over-the- gas is used in over 18 million installations nationwide for home and commercial heating and cooking, road vehicles and industrial lift trucks. These field inspectors maintain that the leakage test effectively requires that piping segments on a cargo tank motor vehicle transporting propane must be tested independently and that leakage past or through a valve is not permitted. In seeking resolution of this matter, the company contacted RSPA/OHMS and received a verbal interpretation that in effect upheld the field inspectors. Such an Hazardous Materials Regulation. interpretation poses enormous problems that make it virtually impossible to comply with the The requirement for an annual leakage test was adapted as part of the HM-183 amendments. At the time this requirement was adopted, the understanding throughout the industry was that the test was to the atmosphere. This understanding was upheld in numerous discussions with OHMS intended to determine there were no leaks of the lading through piping joints and other such tixtures. representatives and industry members as well as association representatives (myself included). In fact, the DOT representatives themselves suggested that leak detector solutions, such as are used to check a domestic piping system, would be a suitable means of checking the propane piping on a lading piping system was required. cargo tank motor vehicle! At no time was there an indication that leak detection through valves in the <<>> The MC-331 specification requires that excess flow valves are required in certain critical points as a means of lading flow control in the event of a major break or separation in the piping system during loading or unloading of the lading, in addition to positive shutoff valves in the lading piping. These excess flow valves have been a required feature of a propane cargo tank for many years. Indeed, they are an essential part of the safety design of the cargo containment system for the vehicle. 1 In the event an excess flow valve is caused to operate, the valve is designed to reopen automatically whenever the piping downstream of the valve is made pressure tight through closure of an intervening positive shutoff valve or other suitable means. In virtually all designs of these excess flow valves, regardless of manufacturer, this automatic re-opening feature is accomplished by allowing a controlled tlow space for a very small amount of propane to by-pass the closed valve. The interpretation of these field inspectors that all valves in the piping system must be tested to 8 determine that they provide positive shutoff and that no leakage past the valve is allowed even though the piping system itself is leak tight to the atmosphere means that all of these excess flow valves will knowledge does not presently exist, at least in a form approved for use on a tank truck. have to be replaced with an excess flow valve that must be manually opened - a device that to our 7 There has not been any adverse experience with present designs for excess flow valves that would even begın to indicate a major re-design of the valve would be in order. The present designs are valves in propane cargo tank motor vehicles would be enormous, especially so since there is no atner simple mechanically and have operated flawlessly for years. The cost of replacing all these operations or safety problems with the present designs. The propane industry remains firm in its belief (1) that the required leakage test is intended to determine that there are no lading leaks to the atmosphere and (2) that test of individual valves in the piping system is not intended nor required. We would appreciate your confirmation that our interpretation and application of §180.407 is correct. Your reply at your earliest convenience would be very much appreciated. We would be glad to discuss this interpretation request further at your convenience. Sincerely, W. H. Butterbaugh, CAE - Director Regulatory Affairs cc: William B. McHenry Gerry Misel Mike Gorham Brian Clayton D. R. Meyers D. N. Myers R. R. Roldan Bruce Swiecicki Field Service Directors Information Copies: Daryl McClendon, Sam McTier, Bob Mattocks, and Doug Rinke ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `4e073d51885315c1458650d6a2171a50ad15fefa79fd30c429e9298bfd87d2d1` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-23T09:55:40.945Z - Document slug: `phmsa-interpretation-98-0604` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "National Propane Gas Association" ], "individuals": [ "Mr. W.H. Butterbaugh, CAE" ], "refIds": [ "98-0604" ], "catalogDates": [ "1998-10-05" ], "catalogParts": [ 180 ], "catalogRowCount": 1, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/60406" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "180.407" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/180407" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/1998/980604.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/1998/980604.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/1998/980604.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/98-0604-458d1799fb.pdf", "pdfArtifactSha256": "5299d9e713c583cc0e2faccb7e8bcbec183ef62705834375296dc8197109316f", "extractedTextPath": "data/sources/phmsa-interpretations/98-0604-458d1799fb.v2.txt", "extractedTextSha256": "f00b6b062d1c4c19bf18ed36fecfb8b9d35a8a0d60490bc03c8008029c7061d9", "pageCount": 2, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```