A submersible pump is a "Pump (fluids)") pump that has an impeller sealed to the casing. The assembly is immersed in the liquid to be pumped. The advantage of this type of pump is that it can provide significant lifting force since it does not depend on external air pressure to raise the liquid.

A "mechanical seal system" is used to prevent the liquid being pumped from entering the motor from causing a short circuit. The pump can be connected with a tube, flexible hose or lowered down rails or guide wires so that the pump sits on a "platen foot coupler", thereby connecting it to the outlet pipe.

Submersible pumps find many uses, single stage pumps are used for drainage, sewage pumping, general industrial pumping and slurry pumping. Submersible pumps are usually placed at the bottom of fuel tanks and are also used for removing water from water wells.

Submersible pumps are also used in fuel tanks. By increasing the pressure at the bottom of the tank, the liquid can be raised more easily than by drawing it in (suction) from above. The most advanced models include a water/oil separator that allows it to be reinjected into the reservoir without having to raise it to the surface.

The system consists of a number of rotating impellers installed in series to increase pressure. The energy to rotate the pump comes from a low-voltage electrical network that drives a motor specially designed to work at temperatures of up to 150 °C.

Special attention is required to the type of submersible pump[1]​ used when using certain types of liquids. In most applications, asynchronous alternating current motors are used that drive a radial centrifugal pump, which may have several stages connected in series. Submersible pumps can also work with suction pipe, placing the pump above the tank level. However, to work they have to be primed, that is, with water, so that the water column connects the pump with the tank. The suction pipe cannot be excessively high so that the pressure in the pump does not decrease excessively and to avoid cavitation in the pump. The pumped liquid, as it circulates around the engine, also cools it. So that the purposes are refreshed. Additionally, if the pump is located outside the tank, there is a possibility that gasoline will leak and could cause a fire. Some pump types are not intended for certain applications, such as pumping hot water or flammable liquids.

The use of submersible pumps in garden fountains and walls called weeping walls is becoming very common throughout the world, with a wide variety of capacities and sizes.[2]​.