What is the purpose of wear rings on a centrifugal pump?

Wear rings are critical components in centrifugal pumps that serve to increase the efficiency of the pump. They are typically located between the impeller and the pump casing, forming a close clearance that minimizes the recirculation of flow. By controlling the amount of liquid that can flow back into the impeller, wear rings help maintain a higher pressure differential across the impeller, which directly translates to improved hydraulic efficiency. This efficiency boost means that the pump can move more fluid with less energy, making it more economical to operate.

While wear rings can also contribute to reducing wear on the impeller and casing, their primary role centers around maintaining efficient flow characteristics. Increased efficiency results in better performance and can lead to prolonged pump life when appropriately used, as it reduces the strain on other components in the system.