Tennessee Wastewater Operator Practice Exam

What occurs to flow from a centrifugal pump when there is a loss of pressure at the discharge end?

1. Increased flow

2. Cavitation in the pump

3. Stagnation of water

4. Consistent pressure maintenance

The correct answer is: Cavitation in the pump

When there is a loss of pressure at the discharge end of a centrifugal pump, cavitation is a significant concern. Cavitation occurs when the pressure of the liquid drops below its vapor pressure, leading to the formation of vapor bubbles. As the pump operates, these vapor-filled cavities can collapse, causing damaging shock waves within the pump. In the context of centrifugal pumps, pressure loss at the discharge can result from various factors, such as blockages, increased resistance in the piping, or changes in system demand. When pressure decreases significantly, the ability of the pump to maintain the flow decreases, and it may start to operate inefficiently. This can create conditions that lead to cavitation, which not only reduces the pump's performance but can also cause physical damage to the impeller and other components over time. While other options may appear related, they do not effectively address the specific issue of pressure loss and its direct correlation to cavitation. Increased flow would suggest that the pump is functioning effectively despite the pressure loss, which is usually not the case. Stagnation of water indicates a complete halt in flow, which is often a result of severe issues not directly linked to just a pressure loss at the discharge. Consistent pressure maintenance suggests that the system is operating