Mr. John P. McGavis — Hazardous Materials Safety Interpretation

Page 1of Transportation U.S. Department 400 Seventh Street, S.W. Washington, D.C. 20590 Research and Special Programs Administration JUN 2 1 2000 Mr. John P. McGavis Ref. No. 00-0157 Specialized Transport Repair, Inc. 100 Commerce Drive Buffalo, New York 14218 Dear Mr. McGavis: This is in further response to your letter, dated May 25, 2000, concerning cargo tank retest requirements under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). You asked whether an MC 307 cargo tank on which the manway cover has been altered by the addition of a 3" nozzle must complete a pressure test before it can be returned to service: After further discussion with technical staff of the Research and Special Programs Administration's Office of Hazardous Materials Technology and the Federal Motor Carrier Safety Administration's Hazardous Materials Division, we have determined that our previous response to your question, in our letter dated June 7, 2000, was in error. The addition of a 3" nozzle to a manway cover is, in fact, a "modification" to the cargo tank because it involves a change to the design and construction of the cargo tank that affects its lading retention capability (see § 180.403 of the HMR). Thus, a Design Certifying Engineer must certify that the modified design for the manhole assembly meets the structural integrity requirements of the DOT 407 specification, and a Registered Inspector must certify that the modified manhole assembly conforms to the DOT 407 specification by issuing a supplemental manufacturer's certificate (see § 180.413(d)(5)). The modified manhole assembly must conform to the requirements for the DOT 407 cargo tank specification in § 178.345-5. In addition, the suitability of a modification that affects the structural integrity of a cargo tank with respect to pressure must be determined by a pressure test (see § 180.413(d)(10)). For the modification of the manway cover that you have described, this requirement may be met by the performance of a bench test of the modified cover, provided that your bench test fixture is representative of the manhole assembly on the cargo tank. You need not complete a pressure test of the entire cargo tank. 180.407 000157#

Page 2I hope this information is helpful. Please accept my apology for any confusion that may have resulted from our previous response. If you have further questions, please do not hesitate to contact this office. Sincerely, Thomas t. allan Thomas G. Allan Senior Transportation Regulations Specialist Office of Hazardous Materials Standards .... cordoned 0:0*7 53****: Hit: 6s.. 4220570%#

Page 3STE 1530020 100 Commerce Drive SPECIALIZED TRANSPORT Buffalo, NY 14218 REPAIR Inc. Phone (716) 827-8265 Fax (716) 827-7231 May 25, 2000 Federal Motor Carrier Safety Administration Gorsky Hazardous Materials Division 400 Tin St. SW Research and Special Programs Administration 5180.407 Washington, DC 20590 00-0157 Mr. Daniel Shelton, a customer. The alteration involves the addition of one 3'" nozzle into the manway cover. Per our conversation today, we are being asked to alter a group of MC307SS cargo tanks for This is to enable connection of these trailers to vapor recovery systems at loading areas. The manway covers are Betts 6-lug Model 8310 and 8355 and possibly other similar models) and are removed from the trailers for the alteration. No welding or other repairs or alterations of the tank shell itself are involved. Alterations are done to ASME and National Board standards under our R-stamp authorization. Our question is, can these covers be bench tested and then reinstalled onto the trailers rather than completing a pressure test of the complete tank trailer? Please advise. Thank you, John P. McGavis#