What are the GPM and PSI for the AFFF pump/motor assembly?

• A. 20 gpm, 50 psi
• B. 40 gpm, 100 psi
• C. 65 gpm, 175 psi
• D. 80 gpm, 200 psi

Answer: (C)

The main idea is understanding what the pump/motor assembly is capable of delivering: how much foam solution can be pumped per minute (GPM) and at what discharge pressure (psi). For an AFFF system, you need enough flow to keep the foam concentrate moving through the system and through the foam proportioner and nozzle, while enough pressure is required to overcome losses in hoses, fittings, and the nozzle so the foam is produced correctly and reaches the fire with a stable foam blanket.

The standard rating for the AFFF pump/motor assembly is 65 gallons per minute at 175 psi. This combination provides a balance of adequate flow and sufficient pressure to operate the foam system effectively. Other options fall outside this established spec, either providing too little flow or too low/high pressure for the system’s design.