Which statement about nozzle output and pump pressure according to the material?

• A. Doubling the pump pressure will double the nozzle output
• B. Doubling the pump pressure will not necessarily double the nozzle output
• C. Pump pressure has no effect on nozzle output
• D. Nozzle output decreases with higher pressure

Answer: (B)

The idea to grasp is that nozzle output isn’t a simple, one-to-one result of pump pressure. A nozzle acts like a fixed opening (an orifice), and the flow through that opening depends on the pressure drop across it. In basic fluid theory, the flow rate through an orifice increases with the square root of the pressure difference. So if you double the pressure, the nozzle output tends to rise, but not by a full factor of two—more like a factor of about 1.4 (roughly 41% more) under ideal conditions. In real systems, losses in hoses, fittings, and elevation further reduce the pressure actually at the nozzle, and the nozzle’s own rating is given at a specific pressure. Because of these factors, doubling the pump pressure will not necessarily double the nozzle output.