Regulationcurrent
49 CFR 179.103-4
-4 Safety relief devices and pressure regulators.
Current as of 2026-08-18 Government source
eCFR editorial compilationAuthoritative but unofficial
View source (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.#