[Code of Federal Regulations] [Title 49, Volume 2] [Revised as of October 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR179.100-10] [Page 1009] TITLE 49--TRANSPORTATION CHAPTER I--RESEARCH AND SPECIAL PROGRAMS ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 179_SPECIFICATIONS FOR TANK CARS--Table of Contents Subpart C_Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) Sec. 179.100-10 Postweld heat treatment. (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. (b) For aluminum tanks, postweld heat treatment is prohibited. (c) Tank and welded attachments, fabricated from ASTM A 240/A 240M (incorporated by reference; see Sec. 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 Sec. 179.100-7(c)(2). [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]