How does elevation affect pump discharge pressure requirements?

• A. Elevation adds to the pressure required to raise water to higher levels, increasing nozzle pressure needs
• B. Elevation decreases pressure required
• C. Elevation has no effect
• D. Elevation affects water temperature

Answer: (C)

The main idea is that discharge pressure needs are driven by the nozzle pressure and the friction losses in the hose, not by the vertical height the water must be lifted. If you know the nozzle requires a certain pressure to achieve the desired spray and you add the hose friction losses, that sum is the discharge pressure you aim for at the pump. The elevation difference between pump and nozzle is a hydrostatic head, but in this framing it’s treated as part of the overall head the pump must develop rather than as an extra nozzle-pressure requirement. So elevation by itself doesn’t change the discharge pressure value you set to achieve the target nozzle performance. In real calculations you still consider head effects, but for the purpose of determining discharge pressure to meet the nozzle’s needs, elevation doesn’t alter the required discharge pressure.