Tennessee Wastewater Operator Practice Exam

What is essential for preventing internal leakage in a centrifugal pump?

1. Seals

2. Wear rings

3. Piping

4. Gaskets

The correct answer is: Wear rings

The correct answer focuses on wear rings, which are critical components in centrifugal pumps designed to minimize internal leakage. Wear rings are fitted between the rotating impeller and the stationary casing. Their primary function is to reduce the gap between these two components, effectively controlling the flow of fluid and preventing it from bypassing the impeller. By restricting the flow, wear rings help maintain the efficiency of the pump and ensure that most of the fluid moves through the designated discharge path rather than leaking back through the spaces that could widen with wear over time. This is especially important in centrifugal pump designs, as any internal leakage can lead to a drop in performance and increased energy consumption. Other options do play roles in the operation of centrifugal pumps: seals help prevent external leakage and protect the bearings, while piping connects the pump to the system and gaskets ensure connections are watertight. However, it is specifically wear rings that address the issue of internal fluid leakage, making them essential for maintaining pump efficiency.