How to deal with the leakage problem of electric Control Valve
Electric control valve is widely used because of its good stability and simple maintenance. It can be designed as a balanced type to eliminate most of the static imbalance force on the valve clack, and has a certain damping effect, which can reduce the vibration caused by fluid flow, and can be used When the pressure difference is relatively large, multi-spring pneumatic film mechanism or electric actuator can be selected. How should we deal with the leakage problem of the electric control valve? Let me share with you five tips and tricks to deal with leakage of electric control valves:
Method one is to increase the sealing grease method; this method is aimed at the valve body that has not yet used the sealing grease, and it can be considered to increase the sealing grease to improve the sealing performance of the valve stem. It is also one of the necessary maintenance procedures to add additional sealing grease during daily maintenance of the electric control valve.
     The second method is to change the flow direction and place P2 at the end of the valve stem; when △P is larger and P1 is larger, sealing P1 is obviously more difficult than sealing P2. Therefore, the electric control valve can adopt the method of changing the flow direction and place P1 in the valve. The rod end is changed to P2 at the stem end, which is more effective for valves with high pressure and large pressure difference. For example, bellows valves should usually be considered to seal P2.
     The third method is to use the lens gasket sealing method; for the sealing of the upper and lower covers, the sealing of the valve seat and the upper and lower valve bodies. If it is a flat seal, under high temperature and high pressure, the sealing performance is poor, causing leakage, you can switch to electric adjustment The valve lens gasket is sealed, and satisfactory results can be obtained.
     The fourth method is to increase the packing method; usually double-layer or multi-layer mixed packing is used to simply increase the number of sealing gaskets, such as increasing the number of gaskets from 3 to 5 to improve the sealing performance of the valve stem, but the electric control valve prevents The leakage effect is not very obvious.
     The fifth method is to replace the graphite packing method; a large number of used four ** packings are suitable for working temperature in the range of -20～200℃. When the working temperature changes greatly between the upper and lower limits, the sealing performance of the electric control valve is obvious Decrease, fast aging and short life span. It is recommended to use flexible graphite packing here to overcome the difficulties that tetrafluoride packing can not bear, and has a long service life, thereby improving the reliability of the seal. Many factories have all changed the tetrafluoroethylene packing to graphite packing, and even the newly purchased regulating valve has replaced the tetrafluorocarbon packing with graphite packing for use. However, graphite packing also has a shortcoming, that is, the hysteresis is large, and some creeping phenomenon occurs at the beginning. In this regard, manufacturers and users must also consider when designing and installing electric control valve equipment.