Why are pumps primed before operation?

Pumps are primed before operation primarily to replace air inside the pump with water. This process is essential because pumps are designed to move liquids, and having air in the system can lead to air locks, which can prevent water from flowing properly. Priming ensures that the impeller and the pump casing are filled with liquid, allowing for efficient movement and suction. When water is introduced into the pump, it creates the necessary hydraulic conditions for the pump to operate effectively, promoting proper function and preventing potential damage.

The process also maximizes the efficiency of the pump. When a pump is fully primed with liquid, it can generate the required flow and pressure more effectively than if it were operating with air present. This makes priming a critical step in preparing the pump for successful operation.