Which device is used to mix foam concentrate with water to form foam?

• A. Foam proportioner
• B. Fire pump
• C. Flow meter
• D. Venturi throat

Answer: (A)

Forming foam requires a device that controls how much concentrate is mixed into the water stream, ensuring the correct dilution for effective foam generation. A foam proportioner is designed to do exactly that: it injects a measured amount of foam concentrate into the water flow and maintains the proper ratio so the resulting foam solution has the right properties for firefighting.

A fire pump just moves water; it doesn’t mix concentrate. A flow meter only indicates flow rate, not the mixing ratio. A venturi throat can be part of devices that entrain concentrate, but by itself it’s not the complete system responsible for maintaining the proper proportion—the foam proportioner is.