The Differences of Reciprocating Pumps, Rotary Pumps And Centrifugal Pumps
Reciprocating pumps and rotary pumps are positive displacement type because they discharge a near constant amount of liquid regardless of pressure. If the discharge valve is closed, they build up a bursting pressure or stall their motor. Centrifugal pumps are nonpositive and fairly low pressure units. Here a closed discharge valve will not cause excessive pressure to build up.
In general, reciprocating pumps are suitable for delivering small quantities at high pressure, rotary pumps are used for moderate quantities at moderate pressure, and centrifugal pumps are more suitable for large quantities at low pressure. Centrifugal pumps, however, can be designed with a number of impellers in series to attain a high final delivery pressure. They are popular because they are very simple in construction, and can produce smooth, constant, nonpulsating discharge.
