In a foam concentrate injection system, activation occurs automatically by what event?

• A. Activation of the main water supply control valve
• B. Manual start by operator
• C. Activation of the foam concentrate feed pump only
• D. Detection device alarm

Answer: (A)

Foam concentrate is added automatically only when there is water flow in the system. When the main water supply control valve opens, water begins to flow through the foam-proportioning device, drawing in foam concentrate and creating the foam solution. This automatic trigger ensures foam is produced only as part of the water stream during system activation. A manual start bypasses automatic operation, and the foam pump alone won’t inject foam without water flow; a detection alarm may alert but doesn’t by itself start the injection.