1) Whether it is the suction side or rear side wear rings, their main purpose is to protect the pump casing or impeller from wear that may lead to direct damage.

2) The wear-resistant ring on the suction side of the impeller is designed to limit the pumping flow of high-pressure fluid from the impeller outlet back to the low-pressure suction side. If the gap at the wear-resistant ring is too large, it will lead to an increase in leakage and a decrease in efficiency.

3) The rear wear ring (if any) is usually used in conjunction with the balance hole (the balance hole passes through the impeller rear cover and communicates with the impeller suction port) to reduce the pressure on the back of the impeller, thereby reducing the axial thrust of the pump rotor (and seal chamber pressure).

4) The Lomakin effect produced by the wear-resistant ring is beneficial to improving the reliability of pump operation.

5) Wear-resistant rings can also improve the stiffness of the pump shaft and extend the service life of components (bearings and mechanical seals).