281. U.S. regulations require cargo pump rooms, on tank vessels handling grades A, B, or C liquid cargo, shall be equipped with power ventilation of the exhaust type. in what amount of time should the ventilation effect a complete change of air?

U.S. tank vessel regulations mandate that cargo pump rooms handling grades A, B, or C liquids have exhaust ventilation capable of completing a full air change in no more than 3 minutes, equivalent to at least 20 air changes per hour, to mitigate fire and explosion risks.