Technical Guidelines

How a Progressing Cavity Pump works

A single external helix or ‘rotor’ oscillates within a stationary double internal helix known as a ‘stator’. This forms a series of cavities 180 degrees apart. As the rotor oscillates, these cavities gently convey liquid from the low pressure suction end to the high pressure discharge end. Pressure is maintained by the contact point between the rotor and stator which is referred to the ‘seal line’. By doubling the length of the rotor and stator [2 stages] the seal line is increased as is the pump’s pressure capability. Typically, a 1-stage pump will be rated for 6 bar g and a 2-stage pump 12 bar g. The flow rate of the pump is determined by rotational speed and the diameter of the rotor and stator.