{"operation":"document","citation":"49 CFR 179.100-10","title":"-10 Postweld heat treatment.","source_type":"regulation","agency":"Pipeline and Hazardous Materials Safety Administration","status":"current","official":true,"published_on":null,"effective_on":"2026-08-18","summary":"(a) After welding is complete, steel tanks and all attachments welded thereto must be postweld heat treated as a unit in compliance with the requirements of AAR Specifications for Tank Cars, appendix W (IBR, see § 171.7 of this subchapter).\n\n(b) For aluminum tanks, postweld heat treatment is prohibi","machine_formats":{"json":"https://regulus.evalyn.ai/document/49-cfr-179-100-10.json","markdown":"https://regulus.evalyn.ai/document/49-cfr-179-100-10.md"},"app_url":"https://regulus.evalyn.ai/document/49-cfr-179-100-10","source_url":"https://www.ecfr.gov/on/2026-08-18/title-49/section-179.100-10","body":"(a) After welding is complete, steel tanks and all attachments welded thereto must be postweld heat treated as a unit in compliance with the requirements of AAR Specifications for Tank Cars, appendix W (IBR, see § 171.7 of this subchapter).\n\n(b) For aluminum tanks, postweld heat treatment is prohibited.\n\n(c) Tank and welded attachments, fabricated from ASTM A 240/A 240M (IBR, see § 171.7 of this subchapter), Type 304L or Type 316L materials do not require postweld heat treatment, but these materials do require a corrosion resistance test as specified in § 179.100-7(c)(2).\n\n[Amdt. 179-10, 36 FR 21345, Nov. 6, 1971, as amended by Amdt. 179-47, 58 FR 50238, Sept. 24, 1993; Amdt. 179-52, 61 FR 28679, June 5, 1996; 67 FR 51660, Aug. 8, 2002; 68 FR 75758, 75759, Dec. 31, 2003]","truncated":false,"body_characters":781}