Five tips to deal with leakage of electric control valve
The first method is to increase the sealing grease method; this method is for the valve body which has not used the sealing grease, so it can be considered to increase the sealing grease to improve the sealing performance of the valve stem. When daily maintenance of electric control valve, adding sealing grease is also one of the necessary maintenance procedures.
The second method is to change the flow direction and place P2 on the stem end. When the △ P is larger and P1 is larger, it is obviously more difficult to seal P1 than P2. Therefore, the electric control valve can adopt the method of changing the flow direction, changing P1 to P2 at the stem end, which is more effective for valves with high pressure and large pressure difference. For example, the bellows valve should usually consider sealing P2.
The third method is to use lens gasket sealing method; for the sealing of upper and lower covers, the sealing between valve seat and upper and lower valve bodies. If it is plane sealing, the sealing performance is poor under high temperature and high pressure, resulting in leakage, so the lens gasket seal of electric control valve can be used, and satisfactory results can be obtained.
The fourth method is to increase the packing method, which is usually in the form of double-layer or multi-layer mixed packing, simply increasing the number of sealing gaskets, such as increasing 3 pieces to 5 pieces, to improve the sealing performance of the valve stem, but the leakage proof effect of the electric control valve is not very obvious.
The fifth method is to replace graphite packing method; a large number of used four * * fillers can be used in the range of - 20 ~ 200 ℃. When the working temperature changes greatly in the upper and lower limits, the sealing performance of the electric control valve decreases obviously, and the aging is fast and the service life is short. The flexible graphite packing is recommended here, which can overcome the difficulties that the four * * packing can not bear, and has a long service life, so as to improve the reliability of the seal. Many factories have changed the packing of four * * into graphite packing, and even the newly purchased regulating valve has replaced the four * * packing with graphite packing. However, graphite packing also has a disadvantage, that is, the return difference is large, and some of them still have crawling phenomenon at the beginning. Therefore, manufacturers and users should also consider the design and installation of electric control valve equipment.