What can cause a pump to operate below its expected discharge rate?

A pump operating below its expected discharge rate can be attributed to several factors, but option B highlights a significant issue. A clogged impeller restricts the flow of fluid through the pump, resulting in decreased efficiency and lower discharge rates. When debris, sediment, or other obstructions accumulate in the impeller, it can hinder the pump's ability to move fluid effectively, leading to reduced performance.

While other factors such as worn bearings, low fluid levels, and improper alignment can also affect pump performance, they do so in different ways. Worn bearings can introduce additional friction and reduce the overall efficiency of the pump, while low fluid levels may introduce issues related to cavitation or lack of prime, which can also result in decreased discharge. Improper alignment affects the mechanical connections and can lead to vibration or misdirection of flow, but a clogged impeller directly obstructs fluid movement and has a more immediate effect on discharge rates. Hence, identifying a clogged impeller as the cause of reduced discharge is critical for troubleshooting pump performance issues effectively.