Wearing rings, also known as wear rings, are components used in centrifugal pumps to minimize the leakage of fluid between the impeller and the pump casing. They are designed to provide a small running clearance between the impeller and the casing, which helps to improve pump efficiency and reduce wear on both components. https://www.growmechanical.com/basic-use-of-wearing-rings-in-centrifugal-pump/