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How to solve the leakage problem of electric control valve
During the use of electric control valves, if leakage occurs, it must be addressed promptly. The following methods can be considered: 1) Increase sealing grease: For valves that have not been applied with sealing grease, consider adding sealing grease to enhance the sealing performance of the valve stem. 2) Increasing packing method: To enhance the sealing performance of the packing on the valve stem, the method of increasing packing can be employed. Typically, a double-layer or multi-layer mixed packing form is adopted. Simply increasing the number, such as from 3 to 5 pieces, does not yield significant results. 3) Replacement of graphite packing method: The widely used PTFE (polytetrafluoroethylene) packing has a working temperature range of -20 to +200℃. When the temperature changes significantly between the upper and lower limits, its sealing performance significantly decreases, it ages quickly, and its lifespan is short. Flexible graphite packing can overcome these shortcomings and has a long service life. Therefore, some factories have completely replaced PTFE packing with graphite packing, and even newly purchased control valves have their PTFE packing replaced with graphite packing before use. However, the use of graphite packing results in a large return difference, and some may even exhibit a creeping phenomenon initially, which must be taken into consideration. 4) Adopting the lens gasket sealing method: For the sealing between the upper and lower covers, as well as between the valve seat and the upper and lower valve bodies, if it is a flat surface seal, the sealing performance may be poor under high temperature and high pressure, leading to external leakage. In such cases, the lens gasket sealing method can be adopted instead, achieving satisfactory results. 5) Replacement of sealing gaskets: Currently, most sealing gaskets are still made of asbestos board, which has poor sealing performance and short lifespan under high temperatures, leading to leakage. In such cases, spiral wound gaskets, "O" rings, etc. can be used instead, and many factories have already adopted them. |
