What is the function of Wear Rings in Pumps ?

The impeller rotates within a pump casing to develop pressure.  To prevent leakage of the medium within the pump, the clearance between the pump and the impeller should be as small as possible.

This small clearance results in occasional contact between the rotating impeller and the pump casing.  This causes wear of the surfaces of both the pump and the impeller at the point of contact.

This can damage the impeller and the pump resulting in expensive maintenance.  To prevent this, wear rings are mounted on both the impeller and the pump casing.

Now, the wear occurs only in the wear rings and not in the actual surface of the impeller and the pump.   These wear rings are relatively inexpensive and are replaced at periodic intervals.