The National Board of Boiler and Pressure Vessel Inspectors — Hazardous Materials Safety Interpretation

Page 11200 New Jersey Avenue, SE Washington, DC 20590 U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration March 4, 2025 Luis Ponce Manager of Technical Services The National Board of Boiler and Pressure Vessel Inspectors 1055 Crupper Avenue Columbus, OH 43229-1183 Reference No. 24-0044 Dear Mr. Ponce: This letter is in response to your May 29, 2024 email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to Department of Transportation (DOT) specification cargo tank repair requirements. Specifically, you state that the National Board of Boiler and Pressure Vessel Inspectors (NBBI) publishes its flagship publication—i.e., the National Board Inspection Code (NBIC)—every two years. You further state that the next edition—for 2025—will see a complete rewrite of Supplement 6 “Repair, Alteration, and Modification of DOT Transport Tanks, ” and that there will be changes to the pressure testing of repairs and alterations to line up with DOT requirements. You ask for clarification on whether “applicable manufacturing specification” means a DOT specification or another code of construction. We have paraphrased and answered your questions as follows: Q1. Does the phrase “applicable manufacturing specification” in § 180.413(b) refer to the original code of construction, such as the American Society of Mechanical Engineers (ASME) Code? A1. No. As specified in § 180.413(b), the suitability of each repair affecting the structural integrity or lading retention capability of the cargo tank must be determined by the testing required either in the applicable manufacturing specification or in § 180.407(g)(1)(iv). The phrase “applicable manufacturing specification” means the authorized DOT specification.#

Page 2Q2. If the answer to Q1 is yes, can the requirements of either the original code of construction or Part 180 be used for repairs by an NBBI “R” stamp certificate holder? A2. See answer A1. We hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, Dirk Der Kinderen Chief, Standards Development Branch Standards and Rulemaking Division#