At hydraulic power plants where short closing times are needed on turbine guide vanes and jets due to technical reasons, we integrate pressure relief valves into lines in order to hinder mechanical overrev and excessive pressure increase. When a stop command is sent to the turbines, they are opening immediately and simultaneously and – as a bypass – re-route the corresponding volume of water directly into the tailwater pool. Then the pressure relief valve is closing for the predefined time frame.

Pressure relief valves are built as a poppet seat valves with an opening tendency and hydraulic drive. The optimal form for the water-guidance components is crucial for operation that is as free from cavitation and vibration as possible. We are making housing and inlet elbow from high quality steel, while we make the gaskets and the pistons from stainless material.