Which sequence correctly describes typical steps to prime a pump?

• A. Open the priming device; fill the suction line with air; ensure the intake is unobstructed and free of air; monitor for leaks; once prime is achieved, close the priming device.
• B. Fill the suction line with water; close the priming device; start the pump.
• C. Open the priming device; fill the pump and suction line with water; ensure the intake is unobstructed and free of air; monitor for leaks; once prime is achieved, close the priming device.
• D. Keep the priming device closed until the pump reaches operating speed.

Answer: (C)

Priming a pump hinges on removing trapped air and establishing a continuous water column in the suction path so the pump can develop suction and avoid air lock. Opening the priming device lets the air exit and water begin to fill the system. Filling both the pump and the suction line with water ensures there are no remaining air pockets that could break the prime. Checking that the intake is unobstructed and free of air helps confirm there’s a clear path for the water to reach the pump. Monitoring for leaks during this process is important because any air leaks will ruin the prime. Once water fully fills the suction path and the prime is achieved, closing the priming device seals the line to maintain the prime during operation.

Other options aren’t correct because starting the pump before priming or leaving the priming device closed prevents air from being expelled and water from filling the suction line, leading to air locks or cavitation.