{"operation":"document","citation":"49 CFR 179.400-11","title":"-11 Welding.","source_type":"regulation","agency":"Pipeline and Hazardous Materials Safety Administration","status":"current","official":true,"published_on":null,"effective_on":"2026-08-18","summary":"(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\n(b) The closure for openings and the circumferential closing joints in t","machine_formats":{"json":"https://regulus.evalyn.ai/document/49-cfr-179-400-11.json","markdown":"https://regulus.evalyn.ai/document/49-cfr-179-400-11.md"},"app_url":"https://regulus.evalyn.ai/document/49-cfr-179-400-11","source_url":"https://www.ecfr.gov/on/2026-08-18/title-49/section-179.400-11","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\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\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\n(d) Each welding procedure, welder, and fabricator must be approved.\n\n[Amdt. 179-32, 48 FR 27708, June 16, 1983, as amended at 68 FR 75763, Dec. 31, 2003]","truncated":false,"body_characters":769}