The "positive" in positive displacement describes the effect of the variable volume chamber on the intake pipe, drawing in a fixed amount of fluid, and then forcing the fluid into the discharge line at higher pressure by reducing the volume of the chamber. Once the fluid enters the cavity, the inlet must be blocked in some way so that the fluid is not simply pushed back through it. Depending on the pump design, this can be done through valves or by moving the contents through the inlet before reducing the pump chamber volume. Again, the discharge must somehow be stopped before the pump starts to suck.

This ability of PD pumps to operate on a single isolated volume allows such pumps to generate high pressures, or move viscous fluids (or even dry materials), or deliver precise volumes, etc., more successfully than centrifugal pumps, despite the higher mechanical complexity and accompanying higher costs. For ordinary fluids that require only low pressure, such as water, centrifugal pumps cannot be beaten, especially in applications with large capacity requirements. Once the decision is made to deploy a PD pump, a number of pump design choices arise.

Positive displacement pump function:

• Access to high pressure, low flow water (electric washing pump)

• Precise volume allocation (air pump)

• Pumping viscous fluids (oil pumps)

• Isolation medium and pump mechanism without seal (peristaltic pump)

• Pump pastes and liquids containing large amounts of solids without damage (rotor pump)

• Variable output rate of hydraulic system (axial piston pump).

PD pumps can be grouped by application, for example, high pressure cleaning pumps or fuel delivery pumps, but grouping them by design helps to understand the working mechanisms that make a particular pump suitable for a particular task. In this paper, positive displacement pumps are divided into two groups: reciprocating PD pumps and radial PD pumps.

The above content introduces what is a positive displacement pump and what is the working principle of KNOLL positive displacement pump. In addition, Shenzhen Oudejie Technology specializes in selling new original German imported KNOLL positive displacement pump, and promises to sell products are new original imported, while providing our customers with quotation, selection, product information and other services.