Water hammer

The result of a pressure surge or high-pressure shockwave created when water is forced to change direction or stop abruptly. Prematurely wears parts and in extreme can cause damage or injury.


To fill the pump chamber with the liquid that is to be pumped, to avoid air locks and motor strain. Pumps are often self-priming.

Head loss

The drop in pressure between the water source to the point of outflow. Too much head loss will prevent the pump from operating efficiently.

Built-in pressure vessel

The chamber where water is stored under pressure ready for use is called a pressure vessel. On some pumps this is fitted within the pump’s outer casing rather than mounted separately.