What components are used to create a flow restriction and prevent excessive circulation of water between the impeller discharge and suction areas?

Wear rings are crucial components in centrifugal pumps that serve to create a flow restriction between the impeller discharge and suction areas. They are typically positioned between the impeller and the pump casing and are designed to minimize the leakage of water back to the suction side of the pump. This helps maintain efficient flow and prevents excessive backflow that could lead to reduced pump performance or even cavitation.

By providing a precise fit and controlled flow path, wear rings contribute to the overall hydraulic efficiency of the pump. If the clearance between the impeller and the wear ring is too large, it can allow too much fluid to circulate back, diminishing the effectiveness of the pumping action. Therefore, wear rings are integral to ensuring that the energy applied to the water is effectively transformed into flow, rather than being wasted by excessive recirculation.

In contrast, components like check valves are used to prevent backflow in a system, but they do not specifically create flow restrictions like wear rings do. Pressure gauges monitor system pressure but do not directly affect flow restrictions, and flow meters measure the rate of flow rather than regulating it. Thus, wear rings uniquely fulfill the requirement of establishing flow restrictions to optimize pump performance.