The progressive cavity pump belongs to the group of rotary positive displacement pumps. These pumps are characterized by the presence of a “rotor” (rotating part) and a “stator” (fixed part).
Inside the stator (comparable to a screw with two principles) the rotor moves (comparable to a screw with one principle), pushing the fluid through the mobile cavities that are created with the reciprocal movement.
The number of stages of the rotor-stator unit determines the pressure that can be obtained.
The diameter of the rotor determines instead the capacity of the pump.