Has a propeller-type of impeller running in a casing. The pressure is developed by the flow of liquid over the blades of impeller.
Diaphragm Pumps also known as Air Operated Double Diaphragm Pump (AODD), are a type of reciprocating positive displacement pump in which liquid is pumped by a reciprocating diaphragm, which is driven by a solenoid, a mechanical drive, or a fluid drive. Other versions are air operated Pump has inlet and outlet check valves. Diaphragm Pumps have good dry running characteristics; they can be up to 97% efficient. Diaphragm Pumps can handle highly viscous liquids.