History Of Positive Displacement Pumps

The evolution of metering pumps-a type of reciprocating positive displacement pump-serves as a representative example of the development of positive displacement water pumps. Key milestones include the invention of the world's first motor-driven metering pump in 1936, the debut of the first hydraulically driven diaphragm metering pump in 1939, the invention of the first electromagnetic metering pump in 1963, and the creation of the first pneumatic metering pump in 1965.

In terms of classification, pumps are generally categorized by their operating principles into positive displacement pumps, kinetic pumps, and other types. Positive displacement pumps operate by utilizing a working element that moves in a reciprocating or rotary fashion within the pump cylinder; this movement causes the working volume to alternately expand and contract, thereby facilitating the intake and discharge of liquid. Among these, pumps with reciprocating working elements are known as reciprocating pumps, while those with rotating elements are known as rotary pumps.