Positive Displacement Pump
Positive displacement pumps are pressure oriented. As the pressure is considerably high, discharge can not be isolated. However Relief valve is used in discharge to relieve over pressure to the system itself. Mostly these pumps are applied in hydraulic services.
Classification:
Rotary Pump:
Gear pump:
Internal gear pump
External gear pump
Vane pump
Lobe pump
Screw pump
Reciprocating Pump:
Piston pump
Plunger pump
Diaphragm pump