What type of valve should not be used in the discharge line of pumps due to flow reversal issues?

The correct choice for the type of valve that should not be used in the discharge line of pumps due to flow reversal issues is the swing check valve. Swing check valves are designed to allow fluid to flow in one direction and automatically close when flow reverses. However, they rely on the weight of a disc that swings on a hinge, which can be problematic in applications where flow conditions are variable or where the pump’s discharge pressure may drop, leading to potential backflow situations.

In pump discharge lines, where consistent flow direction and pressure stability are essential, the use of swing check valves can lead to scenarios where the valve does not seal effectively against reverse flow, allowing water to flow back into the pump. This can cause significant operational issues, including damage to the pump and contamination in the system.

Selecting a proper check valve for pump discharge applications is critical to ensure reliable operation. Spring-loaded check valves, for instance, are often preferred in these scenarios as they have a spring mechanism that ensures the valve closes reliably without relying on flow conditions.