[Code of Federal Regulations] [Title 49, Volume 2] [Revised as of October 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR179.100-10] [Page 1071] TITLE 49--TRANSPORTATION CHAPTER I--PIPELINE AND HAZARDOUS MATERIALS SAFETY 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 (IBR, see Sec. 171.7 of this subchapter). (b) For aluminum tanks, postweld heat treatment is prohibited. (c) Tank and welded attachments, fabricated from ASTM A 240/A 240M (IBR, 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; 68 FR 75758 and 75759, Dec. 31, 2003]