How does a sliding-vane pump create suction and discharge pressure?

A sliding-vane pump operates as a positive displacement pump by utilizing a rotor mounted off-centre within a fixed casing. Rectangular vanes are positioned in slots around the rotor and are thrown outward by centrifugal force during rotation, creating a seal against the casing wall.1

The process of creating suction and discharge pressure occurs as follows:

• Suction: As the rotor revolves, the space between the rotor and the casing expands on the suction side, creating a partial vacuum that draws fluid into the pump.1
• Transfer and Discharge: The fluid is trapped in the space between the rotor and the casing and carried toward the discharge side. As the rotor continues to turn, the available volume in these spaces decreases. This reduction in volume generates an increase in pressure, which forces the fluid out into the outlet line.1

Because the vanes are self-compensating for wear and the pump does not require check valves, it provides a constant output with negligible pulsations.1