{"data":{"id":"us/49-cfr-179.400-11","jurisdiction":"us","citation":"49 CFR 179.400-11","heading":"-11 Welding.","body":"(a) Except for closure of openings and a maximum of two circumferential closing joints in the cylindrical portion of the outer jacket, each joint of an inner tank and the outer jacket must be a fusion double welded butt joint.\n(b) The closure for openings and the circumferential closing joints in the cylindrical portion of the outer jacket, including head to shell joints, may be a single welded butt joint using a backing strip on the inside of the joint.\n(c) Each joint must be welded in accordance with the requirements of AAR Specifications for Tank Cars, appendix W (IBR, see § 171.7 of this subchapter).\n(d) Each welding procedure, welder, and fabricator must be approved.","path":["Title 49—Transportation","Subtitle B—Other Regulations Relating to Transportation","CHAPTER I—PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER C—HAZARDOUS MATERIALS REGULATIONS","PART 179—SPECIFICATIONS FOR TANK CARS","Subpart F—Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A)"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-49.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:34Z","sha256":"9f0237c00fc42af97ad345cc3fcdde9a5b1580f977f7b7930cfd159899f89a4a","source_id":"us-cfr","stale":true,"prev":"us/49-cfr-179.400-10","next":"us/49-cfr-179.400-12"},"notice":"GroundRules: Original legal text. Not legal advice."}