Will the centrifugal pump experience surge again?
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Can a centrifugal pump experience surge again? Under what operating conditions did you encounter it? What harm does it cause to the pump?
Surge is a type of abnormal vibration that occurs in turbine compressors (also known as vane compressors) when the flow rate decreases to a certain level. A centrifugal compressor is a type of turbine compressor, and surge poses a serious threat to centrifugal compressors. Centrifugal pumps experience cavitation; cavitation occurs when the flow rate drops to a certain level.
Who told you that centrifugal pumps can experience surge?
It depends on how you define surge. If surge is defined as a condition in which, at the same pressure, two different flow rates correspond to each other, causing frequent fluctuations in the operating point and thus in both the flow rate and the outlet pressure, then older pumps do indeed experience surge, as their performance curve is bell-shaped; at a certain pressure, two flow rates can exist simultaneously. However, today’s standards for all pumps require that the outlet pressure of a pump be a monotonically decreasing function of flow rate; pumps that meet this requirement will not experience surging, at least in theory.
Surge occurs in turbines, while centrifugal pumps may experience gas locking and cavitation
When a pump is evacuated, gas entrapment and cavitation can occur. Choking refers to compressors; you can understand this by looking at the definition
A performance curve with hump characteristics will experience surge