Submersible pumps are linear positive displacement pumps that are fully submerged in the fluid they are pumping. They are powered by an electric motor situated right above the pumping element. The motor shaft extends down into the well and connects directly to the rotating impeller of the pump. Some key features and components of these pumps are discussed below.

Motor

The electric motor is the power source for the submersible pump. It is air-filled and hermetically sealed to prevent fluid ingress. Motors for submersible pumps are typically continuous duty types made of corrosion-resistant materials like stainless steel. They come in single or three-phase varieties with power ratings ranging from fractional to several horsepowers. Properly sizing the motor to the pumping requirement is important for performance and efficiency.

Impeller

The impeller is the rotating part of the Submersible Pumps that increases the pressure and flow rate of the fluid. Common impeller designs include semi-open, closed, and multi-vane. Impeller selection depends on factors like viscosity and solids content of the fluid. Impellers made from corrosion-resistant metals like brass or stainless steel are able to handle most industrial liquids.

Pump Casing

The pump casing houses the motor and impeller assemblies. It has inlet and discharge ports as well as internal passages to guide the fluid into and out of the pump. Case materials can be cast iron, steel, stainless steel, bronze or polypropylene depending on the application. Centrifugal pumps usually have cylindrical or volute-shaped casings while positive displacement pumps incorporate specific internal geometries.

Power Cable

An insulated power cable running inside the shaft connects the submerged motor to the power source on the surface. Cable jackets are made from oil-resistant and cut-resistant rubber or thermoplastic elastomers. The cable may be armored for additional impact protection in some applications. Intake screens are provided at the bottom of the cable entry to prevent debris ingress.