Jet Pumps

Jet pumps operate on the ejector principle that a stream of water or compressed air is injected into the throat of a venturi nozzle, which produces low pressure and draws additional fluid from an external source into the throat. The merged stream is expelled in the diverging venturi tube and by the time it has reached the outlet end of the tube it acquires considerable pressure head.

                                                Figure : Jet Pump

Small pumps of this type are used to prime centrifugal pumps. They are also manufactured for pumping water from small deep wells. A foot valve is installed in the intake to keep pump primed when not in operation. They are designed to lift water around 60 to 70 meters. The efficiency of such a pump is low. But they are compact and light, making it portable and easy to handle.