[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: 49CFR179.103-4] [Page 1016] 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. 179.103-4 Safety relief devices and pressure regulators. (a) Safety relief devices and pressure regulators must be located on top of the tank near the center of the car on a nozzle, mounting plate or recess in the shell. Through or stud bolts, if used, must not enter the tank. (b) Metal guard of approved design must be provided to protect safety relief devices and pressure regulators from damage. [Amdt. 179-10, 36 FR 21348, Nov. 6, 1971]