Self priming pumps for water & light fuel transfer
A standard pump needs to have a suction pressure to operate. If a pump is situated above the liquid level such as on top of a tank then the pump needs to self prime to draw the liquid in to the inlet. A self priming pump should have the casing filled with liquid prior to start up. Upon starting, the pump creates a vacuum ensuring liquid is drawn towards the inlet of the pump, separating the air from the water. The air is discharged through the outlet with the liquid remaining in the pump until sufficient liquid enters the pump.
The liquid placed in the pump head prior to start up is needed to allow the pump to cool and assist with priming. As well as light fuels and water, self priming pumps can also handle solids, and liquids with entrained air.
Self priming pumps are used for a variety of applications including:-
Light fuel transfer
Inert gas cooling
Air conditioning supply
Self priming water pumps should be positioned as close as possible to the suction surface as the maximum distance any pump is able to self-prime is 10 metres at atmospheric pressure.