What condition occurs if bubbles form in the pump casing?

The scenario of bubbles forming in the pump casing is indicative of pump cavitation. Cavitation occurs when the pressure of the liquid within the pump falls below its vapor pressure, resulting in the formation of vapor bubbles. These bubbles can collapse violently as they move into areas of higher pressure within the pump, potentially causing significant damage to the impeller and other components, leading to a decrease in performance and efficiency.

Understanding cavitation is important because it highlights the need for maintaining proper fluid flow and pressure conditions in pump systems. Factors such as inadequate suction head, excessive temperature, or high flow rates can all contribute to cavitation.

In contrast, air lock, back pressure, and vortexing involve different mechanisms. Air lock refers to the situation where air becomes trapped in the pump or piping, preventing liquids from flowing properly. Back pressure is the resistance that the pump experiences while trying to move fluid through a pipeline, which can affect its operation but does not directly involve the formation of bubbles in the pump casing. Vortexing happens when the fluid surface creates a vortex, which may lead to inadequate suction at the pump intake but does not specifically refer to the condition of bubbles forming within the pump casing itself.