What are the common symptoms of air entrainment in a pump?

Air entrainment in a pump leads to specific symptoms that are indicative of the issue. When air enters the pump, it causes a significant disruption in the flow of the fluid being pumped. This disturbance often results in unusual operational sounds, such as pinging or knocking noises, which occur as the air bubbles pass through the impeller. Additionally, the presence of air decreases the hydraulic efficiency of the pump, potentially leading to a loss of flow.

This condition can significantly affect performance, as the pump may struggle to maintain its intended throughput due to the mixed gas and liquid. The loss of flow is particularly critical because it indicates that the pump is not functioning as designed, which could result in inadequate pressure delivery or even damage to the pump components if not addressed in a timely manner.