Positive Displacement Pumps

Positive Displacement Pumps

Positive displacement pumps are a type of pump that works by trapping a fixed amount of fluid and then forcing it through the pump's outlet. Unlike centrifugal pumps, which rely on the kinetic energy of the fluid to move it through the pump, positive displacement pumps use mechanical means to move the fluid. This makes them particularly useful for applications where a high degree of accuracy and control is required, such as in the chemical, pharmaceutical, and food processing industries. There are several different types of positive displacement pumps, including rotary, reciprocating, and diaphragm pumps. Rotary pumps, such as gear and lobe pumps, work by using rotating gears or lobes to trap and move the fluid. Reciprocating pumps, such as piston and plunger pumps, use a piston or plunger to move the fluid back and forth within a cylinder. Diaphragm pumps use a flexible diaphragm to move the fluid. One of the key advantages of positive displacement pumps is their ability to maintain a consistent flow rate, regardless of changes in pressure or viscosity. This makes them ideal for applications where precise control of fluid flow is critical. Positive displacement pumps are also able to handle a wide range of fluids, including those that are viscous, abrasive, or contain solids. However, there are also some limitations to positive displacement pumps. They are generally less efficient than centrifugal pumps, and may require more maintenance due to the mechanical components involved. They are also not well-suited for applications where a high flow rate is required.

rotary pumps, reciprocating pumps, diaphragm pumps, flow rate, viscosity

— Patrick Lewis

CITATION : "Patrick Lewis. 'Positive Displacement Pumps.' Design+Encyclopedia. https://design-encyclopedia.com/define/positive-displacement-pumps?E=402084 (Accessed on October 14, 2026)"