154.701—Cargo pressure and temperature control: General.
Except as allowed under § 154.703, cargo tanks must:
(a)
Have their safety relief valves set at a pressure equal to or greater than the vapor pressure of the cargo at 45 °C (113 °F) but not greater than the MARVS under § 154.405; or
(b)
Be refrigerated by a system meeting § 154.702, and each refrigerated incompatible cargo refrigerated by a separate system.