How can you confirm that the nozzle is receiving the correct pressure?

• A. By comparing the discharge gauge reading to the nozzle pressure reading and accounting for friction losses along the line.
• B. By measuring the water temperature at the nozzle.
• C. By checking the water color.
• D. By counting gallons pumped.

Answer: (A)

The key idea is that the pressure at the nozzle must be what the nozzle is designed for, but the pump’s discharge pressure isn’t the same once water travels through hose and fittings. To confirm the nozzle is receiving the correct pressure, you compare the pump discharge pressure to the actual nozzle pressure, accounting for friction losses along the line. In practice, you either read a nozzle pressure gauge at the nozzle or calculate nozzle pressure by subtracting the hose friction losses (and any elevation or fitting losses) from the pump discharge pressure. If the resulting nozzle pressure matches the target for that nozzle, the nozzle is receiving the correct pressure. This approach directly ties the measured pressures to nozzle performance and spray characteristics.

Measuring water temperature, checking color, or counting gallons pumped do not provide information about pressure at the nozzle, so they won’t confirm whether the nozzle is correctly pressurized.