1. Block water flow during turbine inspection and overhaul2. Reduce the water leakage of the unit when the turbine is shut down3. Close the inlet valve to prevent the unit from escaping when the guide vane fails
The turbine inlet valves is included three types:1. Butterfly valve is suitable for Francis turbines2. Spherical valve is suitable for the high-head impulse type units3. Gate valve is used in low cost, and mostly for small unitsThere are four modes of operation: manual, electric, oil pressure and water pressureThe heavy hammer butterfly valve and spherical valve are used oil pressure or water pressure when they are opening, and rely on the heavy hammer to close automatically when they are closing The action is reliable and the closing time is adjustable It is widely used at present
