What is a requirement for the operation of positive displacement pumps?

The operation of positive displacement pumps is characterized by their ability to move a fixed amount of fluid with each cycle of the pump. A relief valve is crucial in this process because it serves to protect the system from excessive pressure. When a positive displacement pump operates, it can generate very high pressures if there is a blockage or a closed discharge. Without a relief valve, this could lead to damage of the pump, pipes, or other components of the hydraulic system.

The relief valve ensures that if the pressure exceeds a predetermined level, the excess fluid can be redirected or discharged safely, thus preventing damage and maintaining safety within the system. This feature is fundamental for the reliable and safe operation of positive displacement pumps in various applications.