Abstract: An apparatus for use in a method for discharging leakage water from guide vanes of a reversible hydraulic machine when the guide vanes are fully closed under the water surface of a runner being depressed comprises a runner connected to a main shaft of the hydraulic machine and covered with upper and lower covers, a plurality of guide vanes arranged at a peripheral portion of the runner, first and second discharge pipes provided with first and second discharge valves and arranged so as to connect a discharge conduit and a runner chamber formed between the runner and one of the covers, and a device for operating said discharge valves. A leakage water discharge method is carried out in accordance with such control mode as that the first and second discharge valves are both opened when the runner rotates in a power generation direction and one of the discharge valves is opened when said runner rotates in a pumping-up direction.

Abstract: In a method of operating a pump turbine, compressed air is supplied into a runner chamber of the turbine and a leakage drain valve is opened of a guide vane at the time of starting the pump turbine to force downwardly the level of the water in the runner chamber and to rotate a runner of the pump turbine in air, the compressed air in the runner chamber is exhausted when the rotating speed of the runner reaches a rated speed for the pump operation, thus filling the runner chamber with water. The water containing a large quantity of dissolved oxygen and contained near the periphery of the runner is drained into a spillway through a pipe for draining water leakage through the guide vanes, priming pressure in the runner chamber is detected and a leakage drain valve in the drain pipe is closed after a predetermined time from the detection of the priming pressure.

Abstract: In a water wheel turbine or pump in which a guide vane arm is connected to a link through a fracturable pin, a plurality of recesses are provided in the cover of the water wheel turbine or pump along the path of movement of the pin for receiving the fractured portion of the pin thereby locking the guide vane arm to the cover.