Gear pump

In the positive displacement pump the movement of the fluid is forced by reducing the volume of the pump chamber.

Screw pumps belong to the group of rotary positive displacement pumps.

Plunger pumps have a displacement body (plunger) which performs an axial movement in the pump working chamber.

Diaphragm pumps are usually regarded as a special type of reciprocating piston pumps.

Rotary lobe pumps belong to the group of rotary positive displacement pumps.

Reciprocating piston pumps (also oscillating pumps) are a group within the positive displacement pumps where the volume of the pump chamber is periodically changed by an axial movement of the inner part (piston).