What type of pump is designed to operate for short periods of time with a closed valve?

The correct answer is a centrifugal pump. Centrifugal pumps are designed to move fluids by converting kinetic energy, generated by the rotation of a pump impeller, into hydraulic energy. They operate efficiently when there is a continuous flow of water through the system. When it comes to operating under closed valve conditions, centrifugal pumps can be at risk of running in a deadhead situation. This occurs when fluid cannot exit the pump, which can lead to overheating and damage if sustained for too long. However, they are generally used for applications that require the movement of large volumes of fluid quickly and are able to operate effectively for short bursts, even under conditions where the valve is closed temporarily.

When comparing to other types of pumps, positive displacement pumps and piston pumps can handle situations where they are required to pump against a closed valve for longer periods without damage, as they can build pressure without relying on flow. Gear pumps, while they are also positive displacement pumps, have similar characteristics and concerns as piston pumps in this regard. This means that while they can operate against a closed valve, they often do not function optimally under those conditions, making centrifugals best suited for short-duration operations in such scenarios.