What is the primary function of check valves on the discharge side of a centrifugal pump?

The primary function of check valves on the discharge side of a centrifugal pump is to prevent water in the discharge line from flowing back into the pump. These valves act as one-way gates that only allow fluid to flow in a designated direction, which is essential for maintaining the pump's efficiency and protecting it from damage.

When a centrifugal pump is operating, it generates pressure to move water or other fluids through the discharge line. If there were no check valve in place, any decrease in pressure or shutdown of the pump could cause the fluid to flow back towards the pump, potentially leading to conditions such as water hammer, reduced pump efficiency, or even damage to the pump components. By allowing fluid to flow out while preventing it from returning, the check valve ensures that the pump operates smoothly and effectively, maintaining the required flow and pressure in the system.

Other options could involve actions that do not directly contribute to the primary purpose of the check valve in this application. For example, allowing air to escape, measuring pressure, or increasing discharge pressure are functions typically associated with other components or devices within a pumping system but do not address the specific role of check valves.