Which type of pump can tolerate having its discharge valve closed for a short period while running without serious damage?

A centrifugal pump is designed to handle varying flow rates effectively and can tolerate temporary changes in discharge conditions, such as when the discharge valve is closed. This is mainly due to the way centrifugal pumps operate, utilizing a rotating impeller to move fluid. When the discharge valve is closed, the pump can still run without causing major damage because the internal pressure can build up to some extent without cavitation or overheating occurring immediately. However, running a centrifugal pump under these conditions for extended periods is not advisable, as it could lead to issues like overheating or damage over time.

In contrast, diaphragm pumps and progressive cavity pumps do not handle closed discharge conditions well, as they rely on positive displacement and can experience damage from excessive back pressure. Gear pumps, similarly, can be affected negatively if the discharge is shut off, as they depend on the continuous movement of fluid to maintain lubrication and prevent wear. These characteristics make the centrifugal pump uniquely suited for short periods of operation with the discharge valve closed without immediate severe damage.