QJ Deep Well Submersible Pump: How It Works and Where It Fits

A QJ deep well submersible pump is a multistage pump and an electric motor joined into one unit and lowered into the well. Because the motor works under water, there is no long shaft and no pump house at the top of the well. That is the main reason it has become the usual choice for drawing groundwater.

What a complete set includes

• The pump end, with several impellers stacked one above the other
• The submersible motor below it, cooled by the water flowing past
• A submersible cable running up to the surface
• The riser pipe that carries the water up and holds the pump
• A control cabinet with protection, a voltmeter and an ammeter

How it lifts the water

Each impeller spins the water outward and passes it up through a guide vane to the next impeller. Every stage adds pressure, so the head of the pump grows with the number of stages. The strainer at the inlet keeps larger debris out, and the pump sits between the motor and the riser, so the water also flows around the motor and keeps it cool.

Motor types

Submersible motors are built in four ways: dry, semi-dry, oil-filled and wet (water-filled). A water-filled motor is filled with clean water before installation and drained before storage in freezing weather. Our 100QJ pumps use a sealed oil-filled motor instead, which must not be filled with water.

Why people choose it

• Pump and motor run under water as one unit, quietly and with nothing to align at the surface
• It works in steel, concrete or simple earth wells, and the riser can be steel or, within its pressure limit, plastic
• Installation is simple and takes little space; no pump house is needed

Sizes and performance

Our QJ range runs from the 100QJ, for wells of 100 mm (4 inch) and up, to the 200QJ for 200 mm (8 inch) wells. Flow covers 2 to 50 m³/h, head goes up to 450 m, and motors from 0.75 to 45 kW. Every model, with its current, outlet and cable size, is in the QJ selection table.

Typical uses

Farm irrigation, drinking water for villages and livestock in hill areas, water supply for towns, factories and building sites, and lifting water from rivers, reservoirs and canals. Send us the well diameter, the water depth and the flow and head you need, and we will select the pump and the number of stages.