Which type of water-based system employs a proportioning valve?

• A. Deluge System
• B. Wet Pipe System
• C. Foam System
• D. Dry Pipe System

Answer: (C)

The main idea is that a foam fire suppression setup needs to mix a foam concentrate with water to create a foam solution. To do this accurately, it uses a proportioning device (a valve or similar mechanism) that meters the concentrate into the water at the correct ratio, ensuring the foam blanket forms properly over the fire. Foam systems are designed specifically to handle this mixing, with the concentrate stored separately and then fed into the water stream through the proportioning device before distribution through foam nozzles or eductors.

Other water-based systems deliver only water through pipes and sprinklers and do not add foam concentrate. Without foam concentrate to mix in, there’s no need for a proportioning valve, so those systems don’t utilize this feature.