49 CFR §179.300-10 — -10 Postweld heat treatment.
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
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).