A multiversal or deck gun operates at approximately which pressure?

• A. 15 PSI
• B. 50 PSI
• C. 100 PSI
• D. 75 PSI

Answer: (A)

Deck guns are designed to deliver a very large volume of water, not a high-velocity, high-pressure jet. To keep the stream controllable and minimize nozzle reaction while still achieving rapid knockdown, the nozzle pressure is kept relatively low. The great flow comes from the large orifice and the master-stream setup, with friction losses in the hose and any elevation losses accounting for the rest. So, in typical practice, a deck gun operates at a low nozzle pressure, around 15 psi, to maximize flow safely.

Choosing higher pressures would create stronger nozzle reaction and require more careful handling, and much higher pressures aren’t necessary for the massive flow a deck gun is intended to deliver.