Valve leakage will result in the following consequences:
1. Transmission media loss
2. Environmental pollution
3. Production failures, such as the leakage of the control valve will cause chemical products are not allowed to
4. Major accident disaster, such as the safety valve leakage will lead to explosion, leakage of toxic gases, etc.
Solution for leakage of electric control valve.
1) increase the sealing grease method
For the valve does not use the seal grease, consider increasing the sealing grease to improve the performance of the valve stem seal.
2) add filling method
In order to improve the sealing performance of the packing to the valve stem, the method of increasing the filling material can be adopted. Usually adopts the double layer, multi-layer mixed packing form, simply increase the number, such as the 3 to 5, the effect is not obvious.
3) replacement of graphite packing method
Use a lot of PTFE packing, because the working temperature in the range of - 20 to + 200 c, when the temperature in the upper and lower limit, change is large, the seal will be decreased, aging fast and short service life. Flexible graphite packing can overcome these shortcomings and long service life. And some plants will all replaced by PTFE packing graphite packing, or even buy back the new control valve will also be replaced by one of the PTFE packing graphite packing after use. But the use of graphite packing back to the big, at the beginning of some of the crawling phenomenon, which must be taken into account.
4) change direction, set P2 in the stem end method
When p] larger P1 and large sealing P1 obviously than the seal P2 difficult. Thus, it can be take changes in the flow of method, the P1 stem end changed to P2 in the stem end, the high pressure, pressure of the valve is more effective. Such as bellows valves should be considered on the normally seal P2.
5) using lens pad seal method
For the upper and lower cover seal, the valve seat and the upper and lower body of the seal. If the plane seal, under high temperature and high pressure, poor sealing, causing leakage, you can switch to the lens pad seal, can be satisfied with the results.
6) replace the sealing gasket
So far, most of the sealing gasket is still asbestos board, at high temperature, the sealing performance is poor, life is short, causing leakage. Encountered such a situation, can be used to wrap around the gasket, "O" shaped ring, and so on, and now many plants have been used.
