DEVICE FOR CHANGEOVER TO PRESSURE-CONTROLLED OPERATION OF STEAM TURBINE

PURPOSE:To reduce the number of changeover operation staff, by providing a changeover solenoid valve for stopping signal oil from a pressure regulator at the stoppage of pressure-controlled operation and another changeover solenoid valve for supplying an output oil cylinder with signal oil driven by the operation of a pressure-controlled operation starting button. CONSTITUTION:When a turbine is stopped, a solenoid valve SV2 is energized to stop signal oil from a pressure regulator 1 and high-pressure oil directly flows into an output oil cylinder 2 to lock it up at the upper limit. When a pressure- controlled operation starting button P is pressed in a central control room, a solenoid valve SV3 is energized and closed so that signal oil from a pressure signal unit 1 flows into the output oil cylinder 2 only through aneedle valve NV. When the lift of the output cylinder 2 has fallen and a microswitch 3 is operated and the solenoid valve 3 is deenergized, the signal oil is formally regarded as communicating. Since changeover to pressure-controlled operation is enabled in the central control room, the number of operation staff can be decreased.