During testing, where should a gauge be placed to evaluate the hydraulically most remote point in a water spray system?

• A. At the riser
• B. At the hydrant connection near the pump
• C. At the hydraulically most remote nozzle
• D. At the control valve

Answer: (C)

When testing a water spray system, you want to verify the pressure where it matters most—the point that will experience the greatest pressure drop under the design flow. The hydraulically most remote nozzle represents the worst-case location for pressure and flow, because friction losses accumulate along the longest or most resistance-filled path from the pump. Placing the gauge at that remote nozzle shows you the actual pressure available where the system delivers its maximum demand, ensuring every spray head will perform properly. If you measured closer to the pump or at a valve, you could miss a low-pressure condition at the farthest point due to losses along the piping. So, the gauge should be placed at the hydraulically most remote nozzle to accurately evaluate system hydraulics.