(a) The design vapor pressure (Po) of a cargo tank must be equal to or greater than the MARVS.
(b) The Po of a cargo tank must be equal to or greater than the vapor pressure of the cargo at 45 [deg]C (113 [deg]F) if:
(1) The cargo tank has no temperature control for the cargo; and
(2) The vapor pressure of the cargo results solely from ambient temperature.
(c) The Po of a cargo tank may be exceeded under harbor conditions if specially approved by the Commandant (CG-ENG). [CGD 74-289, 44 FR 26009, May 3, 1979, as amended by CGD 82-063b, 48 FR 4782, Feb. 3, 1983]