jetpump

A jet pump is a device that uses a high-velocity jet of liquid to generate suction and move water. It operates on the Venturi principle: when part of the pumped fluid passes through a small nozzle, it accelerates and creates a region of reduced pressure in a surrounding mixing chamber, which in turn draws additional water from the source into the pump.

A jet pump typically consists of a nozzle, a venturi or mixing chamber, a discharge outlet, and one or more check valves. Water from the source is drawn in through an intake, becomes part of the motive jet, and is discharged through the delivery line. In most applications the pump must be primed before starting to establish a water column in the suction line.

Configurations generally fall into shallow-well and deep-well types. Shallow-well jet pumps use a single suction/discharge arrangement to lift water from near the surface. Deep-well jet pumps use a separate suction line to bring water up to the jet assembly, where it is entrained with the motive jet and then delivered to the surface, sometimes via an additional discharge line.

Performance and limitations include a lift limited by atmospheric pressure, typically around 20–30 feet at sea level for unsupplemented suction. Jet pumps are simple and inexpensive to repair and are well suited for small domestic or irrigation needs, but they are less efficient and require priming compared with many centrifugal pumps. Their ability to lift from greater depths is limited without specialized deep-well or multi-stage configurations.