Which valve controls the flow of seawater from the firemain to the proportioner and is controlled by the master SOPV?

Which valve controls the flow of seawater from the firemain to the proportioner and is controlled by the master SOPV?

• A. Provides AFFF concentrate. Color is striped blue/red
• B. Proportions AFFF concentrate and seawater and routes it to sprinklers and hose reels. Color is striped Red/Green
• C. Provides means to activate the system
• D. Hycheck

Answer: (D)

The one-way flow control valve in the seawater line feeding the proportioner is the hycheck. It’s a high-flow check valve that lets seawater move toward the proportioner when the master SOPV is opened, but prevents backflow into the firemain when pressure drops or the system is shut down. The master SOPV handles when the system is activated and pressurized, and the hycheck provides the actual directional control in that path. Other options describe concentrate supply or the general actuation of the system, but they don’t perform the specific one-way flow control from the firemain to the proportioner.

The one-way flow control valve in the seawater line feeding the proportioner is the hycheck. It’s a high-flow check valve that lets seawater move toward the proportioner when the master SOPV is opened, but prevents backflow into the firemain when pressure drops or the system is shut down. The master SOPV handles when the system is activated and pressurized, and the hycheck provides the actual directional control in that path. Other options describe concentrate supply or the general actuation of the system, but they don’t perform the specific one-way flow control from the firemain to the proportioner.