The OPC valve GS020600V function in the steam turbine generator is to quickly close the speed control valve, extraction control valve, and various extraction check valves without interrupting the turbine. There are three types of signals that can trigger the overspeed protection signal action and release two solenoid valves. One is the set signal LDA of the load drop prediction logic, the second is the test signal of OPC, and the third is the overspeed signal of the unit speed exceeding 103%.

OPC oil pressure directly or indirectly acts on the governing valve, extraction adjustment valve, and various extraction check valves to keep them open. When receiving the above three types of overspeed protection signals, the OPC solenoid valve GS020600V acts to release the OPC oil pressure, close the speed control valve, extraction control valve, and extraction check valve, and keep the main steam valve open. When the speed drops to 2950 rpm, the OPC solenoid valve GS020600V closes, the OPC oil pressure returns, the speed control valve opens, and DEH controls the speed again at 3000 rpm. So OPC oil pressure is used to prevent turbine overspeed caused by load rejection or other reasons. There are many modes of OPC, for example, in some power plants, the OPC oil pressure is established to quickly close the regulating valve, and the regulating valve can only be opened when it disappears.

Yoyik also offer other solenoid valves which are frequently used for steam tubine DEH system.
Solenoid Valves GS021600V+CCP115D
3 Way Solenoid Valve 24vdc SV4-10V-0-0-220AC
Solenoid Coil 220v Ac CCS230D 16.5W 230VAC
Solenoid Valve Coil 24vdc Z2804076
Electromagnetic Valve CCP230M 230VDC 19W PAT5002253
MSV Active Solenoid Valve Coil MFB12-37YC AC220V 30W
Normally Closed Solenoid Valve SV1-10V-C-0-00
AST Solenoid Valve Coil AM501-1-0149
24vac Solenoid Valve GS061600V+CCP115D
OPC Solenoid Valve CCP115D 115VAC 19W
Solenoid Coil AM-501-1-0149 110VDC
Over Speed Protection Control Valve OPC SV1-10V-C0-00-240AG
24v Pneumatic Solenoid Valve 6YV
High Speed Solenoid Valve 300AA00126A
Solenoid Valve 5 2 CCP230D 230VAC 22.3W PAT5002253
12v Pneumatic Solenoid Valve 300AA00086A
Normally Open Valve Types Z6206052 VAC110