Question 814 Deck General

The correct answer is D) Pressure vacuum relief valves. Regulations require that cargo tanks in which grades B or C liquids are carried must be vented with pressure vacuum relief valves. This is to prevent the build-up of pressure or vacuum in the cargo tanks, which could potentially lead to tank failure or leakage. Pressure vacuum relief valves automatically open and close to maintain the appropriate pressure in the tank, ensuring the safe containment of the hazardous liquids. The other options, such as flame screens, forced draft blowers, and gooseneck vents, are not the correct required venting mechanisms for cargo tanks carrying grades B or C liquids according to the regulations.