Progressive cavity pumps, also known as helical rotor pumps or cavity pumps, are a type of rotary positive displacement pump that has a single threaded helically shaped rotor turning inside of a double-threaded helically shaped rubber stator.
This produces a progressing cavity that moves the liquid through the pump and creates the pumping action.
Helical rotor pumps are used extensively in sewerage and water treatment plants to pump polymer, sludge and chemicals
Netzsch Progressive Cavity Pumps Operating Principle
They are also used in all types of industrial applications for pumping a wide variety of thin and thick liquids, including corrosive liquids and liquids containing solids.
As progressive cavity pumps can handle difficult, thick and solid laden liquids, they can often be used in applications where no other pump would perform.