What happens to a centrifugal pump at excessive suction lift?

In a centrifugal pump, excessive suction lift can lead to a number of operational issues. When the suction lift—the vertical distance between the liquid source and the pump suction—exceeds the pump's capabilities, several problems arise. The pump may not be able to generate enough pressure to lift the fluid, resulting in cavitation, which occurs when vapor bubbles form in the liquid and collapse violently, causing damage to the pump components. This condition can lead to a situation where the pump fails to operate altogether, as it cannot maintain the necessary flow or pressure.

Understanding the limits of a pump's suction lift is crucial for proper operation; exceeding these limits impairs its function and can result in significant mechanical failures. Hence, the outcome of excessive suction lift is that the centrifugal pump may fail to operate.