Positive displacement pump can be divided into reciprocating pump, plunger pump, rotor pump, diaphragm pump and screw pump

Reciprocating pump: piston pump (single cylinder, multi cylinder)

Plunger pump: (single cylinder, multi cylinder)

Rotor pump: gear type (internal mesh, external mesh);

Diaphragm pump: (pneumatic, electric, hydraulic)

Screw pump (single, double and triple screw);