What must be verified before starting a centrifugal pump?

Before starting a centrifugal pump, it is crucial to ensure that the suction side valve is open and that the pump is primed. Priming is necessary because centrifugal pumps rely on a continuous flow of liquid to maintain suction and prevent damage. If the pump is not primed, air can be trapped inside, which would hinder its ability to create the necessary pressure to draw water into the pump effectively.

Opening the suction side valve allows water to flow into the pump and helps to fill it, ensuring that the impeller has the liquid it needs to function properly. This step is vital for the efficient operation of the pump and to avoid cavitation or damage that can occur when it operates in a dry state.

In contrast, closing all valves or having the system pressurized does not facilitate the proper operation of the pump. Likewise, having the pump completely dry would prevent it from functioning, but preparing the suction side and ensuring it's primed are both fundamental steps that must occur prior to starting the pump.