Electro-hydraulic servo valve used for steam turbine is a key element in the speed control system of steam turbine. It converts electrical signal into hydraulic signal, controls the position of hydraulic actuator, and realizes the speed regulation of steam turbine. SM4-20(15)57-80/40-10-S182 is a typical type of electro-hydraulic servo valve used for steam turbine. Let’s take a look at its function, and how to maintain the valve at the best working condition.

What Can A Servo Valve SM4-20(15)57-80/40-10-S182 Do?

Steam turbine servo valve SM4-20(15)57-80/40-10-S182 can do many things. The steam turbine servo valve can receive the control signal of the turbine speed control system, such as the signal of the governor position sensor or the control signal of the automatic speed control system; It also converts control signals into hydraulic signals to control the movement of hydraulic cylinders or hydraulic motors; Moreover, the steam turbine servo valve can change the position of the speed governing mechanism, achieve the purpose of controlling the speed of the steam turbine, and realize the speed governing of the steam turbine; It can also ensure that the turbine speed accurately follows the change of the control signal to achieve fast and smooth speed regulation.

How to Keep the Servo Valve in Best Function?

To ensure the smooth operation of the steam turbine servo valve SM4-20(15)57-80/40-10-S182, it is necessary to ensure that the power supply is stable, the voltage is accurate, and the frequency is accurate; The hydraulic oil supplied shall be clean, sufficient and stable; The connecting pipeline shall be well sealed without leakage; All parts shall move flexibly and accurately without jam and interference; The control system shall be normal and can accurately receive and output control signals; Regularly maintained to ensure reliable operation of servo valve.

What to do if repair is needed?

The steam turbine servo valve SM4-20(15)57-80/40-10-S182 needs regular maintenance and cleaning during use, but some problems need to be noticed during maintenance and cleaning. During maintenance, it is necessary to check whether each component is normal, damaged or worn, especially the position sensor, solenoid valve and hydraulic cylinder, and timely replace or repair the defective components to ensure the reliable operation of the servo valve. However, due to the hydraulic oil in the servo valve during cleaning, dirt and carbon deposit will be generated after long-term use, and regular cleaning is required. Special cleaning fluid can be used to clean the servo valve one by one after disassembly. The dirt on the part with carbon deposit shall be thoroughly removed, and then the assembly and tested test shall be carried out to ensure that the servo valve is cleaned before it is put into use.

When replacing the servo valve SM4-20(15)57-80/40-10-S182, we need to do the following five points. First, turn off the power supply of the steam turbine and the control valve servo valve to remove the residual pressure of the system; Secondly, according to the connection mode of the control valve servo valve, remove the connecting pipeline and cable in steps; Third, use the lifting device to lift out the old control valve servo valve and lift in the new control valve servo valve; Fourth, according to the original connection method, install pipelines and cables step by step and check whether they are well connected; Finally, power on and test run the control valve servo valve to check whether everything is normal before putting it into use.