Positive displacement pump relies on piston, plunger, diaphragm, gear or vane, and other working parts to reciprocate or rotate in the pump body, so that the volume of several working chambers in the pump body changes periodically, and alternately sucks and discharges liquid. kind of pump. It has the characteristics of low revolutions, high efficiency, strong self-priming ability, stable operation, and some pumps can be preheated. It is widely used in the transportation of high-viscosity media.
Positive displacement pumps can be divided into two categories: reciprocating pumps and rotary pumps. Among them, reciprocating pumps include piston pumps, plunger pumps, and diaphragm pumps; rotary pumps include gear pumps, screw pumps, and rotor pumps. Usually, the displacement pump can change the flow rate by adjusting the stroke or speed; once the output flow is stable after adjustment, the pump can be used as a metering pump.