In the fields of thermal power generation, industrial drive and gas turbine, steam turbine is the core power equipment, and its safe and stable operation is directly related to production efficiency and equipment life. The overspeed protection control (OPC) system is the “last line of defense” to ensure the safety of steam turbine. As the core actuator of the OPC system, the OPC solenoid valve 165.31.56G03 has become an indispensable part of modern steam turbine safety control with its fast response and high reliability.

OPC solenoid valve 165.31.56G03 is specially designed for turbine overspeed protection. Its core functions include:

1. Quickly cut off the power source: By closing the main steam valve or regulating valve, the working fluid is blocked from entering the turbine;

2. Redundant safety guarantee: Some systems adopt a dual-valve parallel design, which can still trigger protection when a single valve fails;

3. Accurate response control: Collaborate with the speed sensor and PLC/DCS system to achieve threshold triggering and action synchronization.

The OPC solenoid valve 165.31.56G03 adopts modular design, and the main components include:

- Valve body and valve core: the material is mostly 316 stainless steel or alloy steel, resistant to high pressure (up to 20MPa) and high temperature (medium temperature ≤120℃);

- Electromagnetic drive unit: high magnetic permeability coil with low friction valve core to ensure the action time ≤50ms;

- Spring reset mechanism: automatic reset after power failure to avoid failure to recover after misoperation;

- Sealing component: polytetrafluoroethylene (PTFE) or metal hard sealing structure, taking into account oil resistance and long life.

OPC solenoid valve 165.31.56G03 usually adopts “normally closed” design (please refer to the model description for details), and its working process is as follows:

1. Normal working condition: the solenoid valve is in the closed state, and the hydraulic system maintains the opening of the regulating valve;

2. Overspeed trigger: When the speed sensor detects an overspeed signal, the control system sends a 24VDC (or 110VDC) pulse to the solenoid valve;

3. Valve action: The solenoid coil is energized to generate magnetic force, overcome the spring force to pull the valve core, quickly release the control oil pressure, and force the main steam valve to close;

4. System reset: After the fault is eliminated, the solenoid valve is de-energized, the spring pushes the valve core to reset, the oil pressure is rebuilt, and the turbine returns to a controllable state.

Typical application scenarios

1. Thermal power generating units: In large units of 600MW and above, the OPC solenoid valve 165.31.56G03 is linked with the DEH (digital electro-hydraulic control system) to control the high-pressure cylinder (HP) and the intermediate-pressure cylinder (IP) regulating valves to prevent overspeed after load shedding.

2. Gas turbine combined cycle: Gas turbines have a higher risk of delayed fuel cut-off, and the OPC valve needs to act synchronously with the fuel control valve to ensure that the speed drops to a safe range within 0.5 seconds.

3. Industrial drive steam turbine: Back-pressure steam turbines used in petrochemical, papermaking and other fields to prevent overspeed accidents caused by process abnormalities.

As the “ultimate guardian” of the steam turbine safety chain, the performance of the OPC solenoid valve 165.31.56G03 directly determines whether the unit can escape danger in critical moments. In the future, with the advancement of materials science and control technology, OPC valves will continue to make breakthroughs in response speed, environmental adaptability and intelligence, providing more reliable safety protection for the power and industrial fields. In actual applications, users need to strictly follow the manufacturer’s specifications and formulate scientific maintenance strategies based on working conditions to maximize their protection effectiveness.

By the way, we have been supplying spare parts for power plants around the world for 20 years, and we have rich experience and hope to be of service to you. Looking forward to hearing from you. My contact information is as follows:

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