What is the master stream gpm at 80 psi?

• A. 600 gpm @ 80 psi
• B. 800 gpm @ 80 psi
• C. 1000 gpm @ 80 psi
• D. 500 gpm @ 80 psi

Answer: (D)

Master streams deliver water at a fixed nozzle pressure, and the flow depends on the nozzle size and the design of the device. At the standard nozzle pressure used for master streams (80 psi), the typical, tested flow is about 500 gallons per minute. This rating comes from the performance charts firefighters learn for portable monitors and deck guns. Pushing more flow at the same 80 psi would require a larger nozzle opening or higher pressure, and equipment or hydraulics at 80 psi generally can’t sustain 600, 800, or 1000 gpm. So 500 gpm at 80 psi is the expected, practical rating.