Question 1067 Deck General

The correct answer is B) Pressure vacuum relief valves. The U.S. regulations require that cargo tanks in which grades B or C liquids are carried must be vented with pressure vacuum relief valves. This is because these liquids are considered flammable, and pressure vacuum relief valves are designed to automatically open and close to maintain the appropriate pressure within the cargo tank, preventing the buildup of dangerous pressure or vacuum. The other options are incorrect because: A) Flame screens are not sufficient for venting flammable liquids, C) Gooseneck vents do not provide the necessary pressure regulation, and D) Forced draft blowers are not the required method for venting flammable cargo tanks.