What occurs when you close the discharge on a centrifugal pump?

When the discharge of a centrifugal pump is closed, the pump indeed enters a condition known as "deadheading." This refers to the scenario where the pump is still running, but there is no flow of liquid through the discharge line because it is blocked. As a consequence of this blockage, the pressure builds up within the pump casing and impeller.

Since centrifugal pumps are designed to move fluids by converting rotational energy into hydrodynamic energy, when the discharge is closed, the energy generated by the pump has nowhere to go. This can lead to several issues, one of which is overheating. The motor and pump components can become excessively hot because they continue to run without effectively performing their job of transferring fluid. This excessive heat can damage the pump seals, bearings, and even the motor if the situation persists.

Understanding this behavior is crucial for safe and efficient pump operation. In practice, operators must monitor the condition of the pump and may need to implement safety measures like automatic shut-off systems or alarms to prevent damage to the pump during such conditions.