If all discharge gates are shut down, you may lose prime due to small air leaks in the system. It is recommended to keep water flowing to ensure prime is not lost.

• A. True
• B. False
• C. Sometimes true
• D. Not related

Answer: (A)

Priming a centrifugal pump relies on keeping a continuous water column in the priming/ suction path and preventing air from entering the system. When all discharge gates are shut, the pump isn’t flowing water, and tiny air leaks in the suction or priming lines can be drawn into the pump as it tries to develop suction, causing the prime to be lost. Keeping water moving maintains stable pressures and keeps the priming circuit filled, so air is less likely to be drawn in. That’s why this practice is recommended.