{"operation":"document","citation":"00-0190","title":"Design Certifying Engineer — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2000-08-09","effective_on":null,"summary":"00-0190 response to Design Certifying Engineer concerning 178.345.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-00-0190.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-00-0190.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-00-0190","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2000/000190.pdf","body":"<<<PAGE 1>>>\n\nU.S. Department\nof Transportation\nWashington, D.C. 20590\n400 Seventh St., S.W.\nResearch and\nSpecial Programs\nAdministration\nAUG - 9 2000\nMr. David Fellows\nDesign Certifying Engineer\nRef. No. 00-0190\n904 Hawks Hollow\nDelafield, Wisconsin 53018\nDear Mr. Fellows:\nThis responds to your letter, dated July 5, 2000, concerning cargo tank specification requirements in\nthe Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you ask about a\ndesign modification to DOT 406 and 407 specification cargo tanks to equip them with an internal\nagitation system.\nYour letter describes a design for an internal agitator that consists of a large rotating shaft installed\nthrough the rear bulkhead of a cargo tank. The design depends on a non-metallic packing gland, or\nseal, to guarantee lading retention capability of the cargo tank. In your opinion, the design does not\nconform to § 178.345-9(h), which prohibits the use of non-metallic pipes, valves, or connections on\nDOT 406 and 407 cargo tanks unless they are outboard of the product retention system.\nYou are correct that the HMR do not specifically prohibit a design modification of the type you\ndescribe. It is difficult for us to evaluate the merits of the specific design in question without seeing a\npicture or design specification. However, as you describe it, it appears that the non-metallic seal is part\nof the tank wall. As defined in § 178.320(a), \"cargo tank wall\" means those parts of the cargo tank\nthat make up the primary lading retention structure. Thus, under § 178.345-9(h), use of a nonmetallic\nseal or packing gland that is not as strong and heat resistant as the material used for construction of the\ncargo tank is prohibited. You are correct that one way to overcome this design deficiency is to provide\na secondary containment device.\nI hope this information is helpful. If you have further questions, please do not hesitate to contact this\noffice.\nSincerely,\nThomas G. Allan\nSenior Transportation Regulations Specialist\nOffice of Hazardous Materials Standards\n178.345\n000190\n\n<<<PAGE 2>>>\n\nDAVID FELLOWS\nGorskel\n128.345\nDesign and Application\n00-0190\nof Bulk Transport\nPetroleum Tank Trailers\nEquipment and Systems\nPneumatic Dry Bulk Trailers\nChemical Tank Trailers\n904 Hawks Hollow\nDelafield, Wisconsin 53018\nD.O.T. Registored D.C.E.\nFax 262/646-2527\nPhone 262/646-5440\ne-mail Davfellows@aol.com\nJuly 5, 2000\nMr. James K. O' Steen\nHazardous Materials Technology DHM 20\nResearch and Special Programs Administration\nU. S. Department of Transportation\n400 Seventh Street S.W.\nWashington DC. 20590-0001\nDear Mr. O'Steen,\nAs you are aware i have spent quite a few years involved in the design, manufacture and sales of\nSpecifications cargo tanks. Currently I am still regularly involved in the Cargo Tank Industry as a consultant\nand as a design certifying engineer.\nI am writing you to express my concer with, what I believe is, an error of omission in the Hazardous\nMaterials Specifications for flammable liquids cargo tanks, specifically Specification DOT 406 and 407.\nSome background information may be helpful. The need to process hazardous waste materials brought on\nby the desire to clean up our environment in the last twenty years has created new industries to deal with\nthese products.\nThe firing of cement mills with a variety of waste flammable liquids is one example. The type of burners\nused, in addition to handling a variety of differing solvents, is also capable of handling waste fuels containing\nas much as fifty percent of waste solids. This creates an ingenious system of ridding society of a variety of\nundesirable waste materials. As an example dry cleaning paper filters contaminated with perchloroethylene\nare ground up and suspended in perhaps contaminated MEK:\nIn order to keep these mixtures of solids and liquids suspended during transport or at unloading,\nSpecification cargo tanks are equipped with a variety of internal agitators. Some are vertical inserted\nthrough the top of the tank, others are horizontal and constructed completely within the cargo tank.\nSome of these designs are well thought out and are successful. They are installed in such a way as to assure\nthe structural integrity and lading retention capability of the Specification tank in which they are installed.\nMy concern is with a design that brings a large rotating shaft through the rear bulkhead of the cargo tank,\nThe design depends on the packing gland to guarantee the lading retention capability of the cargo tank. The\nSpecifications make no mention of such a design, so since this feature is not specifically mentioned, it is\nthought, not to be prohibited\nWinter Address • 14 Majorca Dr. - Rancho Mirage, CA 92270 • Phone 760/202-0435 • Fax 760/321-0574\n\n<<<PAGE 3>>>\n\n-\n•\nMr. James K. O'Steen\npage 2,\nJuly 5, 2000\nIt is my opinion, that such a design seriously compromises the lading retention capability of the cargo tank.\nParagraph 178.345-9(h) prohibits the use of nonmetallic pipes, valves or connections in DOT-406 & 407\ncargo tanks, unless it is outboard of the product retention system.\nIn the case of the design with the packing gland in the rear head, nonmetallic material is part of the \"tank\nwall\", and it is also a part of the containment system. This seems inconsistent with Paragraph 178.345-9(h).\nIf there is merit to having the agitator driven from a source outside the cargo tank, necessitating a packing\nof a failure of the packing gland.\ngland, it would be consistent with the regulations to provide a means of secondary containment in the event\ninconvenient locations\nMy experience has been that leaks in cargo tanks seem to occur at very inappropriate times and at very •\nIf the Research and Special Programs Administration has a concern about the lading retention capability of\ncontainment device.\nthis design, I believe there is logic in the Specifications to either not allow it, or to require a secondary\nTam sending a copy of this memo to Bill Quade at the Federal Motor Carrier Safety Administration in the\nevent that they also may have a concern with this design. They may determine that the Specifications, as\nwritten, precludes the use of nonmetallic materials as apart of the tank wall.\nThank you for reviewing my opinions and concerns. I am interested in knowing your opinion.\nVery truly yours\nDaniel Fellars\nDavid Fellows\nDesign Certifying Engineer, CT-5132\nC.C.\nMr. William A. Quade, Chief\nHazardous Materials, Room 3419\nFederal Motor Carrier Safety Administration\nU.S. Department of Transportation\n400 Seventh Street S. W.\nWashington, DC 20590-0001","truncated":false,"body_characters":6593}