U.S. Code of Federal Regulations
Regulations most recently checked for updates: Feb 24, 2020
(a) Tanks must be of fusion welded construction, cylindrical in shape with seamless heads concave to the pressure. Tank shells may be of seamless construction.
(b) Tanks must be designed, constructed, certified, and stamped in accordance with Section VIII of the ASME Code (IBR, see § 171.7 of this subchapter).
(c) Tanks including all permanent attachments must be postweld heat treated as a unit.