1) increase the sealing grease method on the unused sealing grease valve, consider increasing the sealing grease to improve the valve stem sealing performance. 2) Increase the packing method To improve the sealing performance of the packing on the valve rod, increase the packing method. Usually double, multi-layer mixed filler, simply increase the number, such as the 3 to 5, the effect is not obvious. 3) The replacement of graphite packing PTFE used in large quantities due to its operating temperature in the range of -20 ~ +200 ℃, when the temperature in the upper and lower limits, when the change is large, the sealing will be significantly reduced, aging fast, life short. Flexible graphite filler can overcome these shortcomings and long service life. Therefore, some factories will be all PTFE filler to graphite packing, and even replaced the new control valve which will be replaced by graphite packing PTFE packing used. However, the use of graphite packing back to the large, sometimes some crawling phenomenon, which must be considered. 4) to change the flow, set P2 in the stem end method when △ P larger, P1 and larger, the seal P1 is obviously more difficult than the seal P2. Therefore, you can take to change the flow of the method, the P1 end of the rod at the end of the P2 in the valve stem, which is high pressure, large pressure valve is more effective. Such as bellows valve should normally be considered sealed P2. 5) The lens pad seal method for the upper and lower lid seal, valve seat and the upper and lower valve body seal. If the plane seal, under high temperature and pressure, poor sealing, causing leakage, you can use a lens pad seal, can be satisfied with the results. 6) Replace the gasket So far, most of the gasket is still asbestos board, at high temperatures, poor sealing performance, short life expectancy, causing leakage. Encountered this situation, you can use the spiral wound gasket, "O" ring, and now many factories have adopted.
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