46 CFR § 38.25-10
Safety relief valves—TB/ALL
April 15, 2021
(a) The cargo tank safety relief valves shall be inspected at least once in every 2 years.
(b) The safety relief valve discs must be lifted from their seats in the presence of a marine inspector by either liquid, gas, or vapor pressure at least once every 5 years to determine the accuracy of adjustment and, if necessary, must be reset.
[CGFR 66-33, 31 FR 15269, Dec. 6, 1966, as amended by CGD 95-027, 61 FR 26000, May 23, 1996]