What purpose do wear rings serve in a pump?

Wear rings play a crucial role in maintaining the efficiency and performance of a pump by reducing the clearance between the impeller and the casing. This close clearance is essential because it minimizes the possibility of leakage from the high-pressure side to the low-pressure side of the pump. When wear rings are installed, they provide a controlled clearance that helps maintain the proper fluid flow through the pump while also reducing the energy losses associated with recirculation of fluid. Over time, wear rings can degrade, which increases the clearance and can lead to a reduction in overall pump efficiency. Thus, the primary function of wear rings is to ensure effective sealing and efficiency within the pump system by controlling the gaps that can form as components wear with use.