Drinking water standards as stipulated by the Water Regulations Advisory Scheme, mandatory in many applications involving mains supply.

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.

The differential between the surface level of the water source to the water discharge point.

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.

The deepest level at which the pump can be submerged.

Rotating component of a pump with vanes that compress the water to increase water pressure.

The pressure resulting from a column of liquid acting under gravity.

The difference in height between the water source to the point of outflow.

The total pressure of water flowing in a system, comprised of two parts – vertical rise and friction 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.

The maximum height that a pump can move fluid against gravity

The pressure needed to overcome loss of force while the water travels through pipework.

Running the pump without priming. Causes overheating and mechanical/electrical failure.

Allows the flow rate to be regulated

Progressively increases the electrical power to the pump for a ‘soft start’ that reduces pump wear, power consumption and water hammer.

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.

If the pump runs dry it tries again in 30 minutes, then hourly for the next three hours, again after six hours and then every 24 hours.

Adjusts the flow rate of the pump, separately to adjusting the pressure.

A sealed unit that can be entirely submerged in water, not placed externally.

Starts and stops the pump automatically when the float reaches adjustable minimum/maximum parameters

If a self-priming pump is started but fails to prime, it will cut off to prevent dry running.

Allows water to flow in only one direction and prevents backflow if outlet pressure exceeds inlet pressure.

Pump containing a series of impellers that progressively increase the water pressure.

Measures the flow rate of the liquid.

Switches off the pump when a given water pressure is reached.

Protection from overheating and mechanical/electrical failure when a pump fails to prime.