The Solutions To The Leakage Of The Control Valve (Regulating Valve) -- I

The Solutions To The Leakage Of The Control Valve (Regulating Valve) -- I

01 Add sealing grease method

For valves that do not use sealing grease, consider adding sealing grease to improve the stem sealing performance.

02 Add packing filler method

In order to improve the sealing performance of the packing to the valve stem, the method of adding packing can be adopted. Usually it is in the form of double-layer and multilayer mixed fillers, and simply increasing the number, such as increasing from 3 to 5, the effect is not obvious.

03 Replacement of graphite packing method

A large number of tetrafluoroethylene fillers are used in large quantities, because their working temperature is within the range of -20～+200℃. When the temperature is at the upper and lower limits and the changes are large, the sealing performance is obviously reduced, the aging is fast, and the life is short.

Flexible graphite filler can overcome these shortcomings and has a long service life. Therefore, some factories all changed the tetrafluoroethylene packing to graphite packing, and even the newly purchased regulating valve also replaced the tetrafluorocarbon packing with graphite packing for use. However, the use of graphite packing has a large hysteresis, and some creeping phenomenon occurs at the beginning, which must be considered.

04 Change the flow direction and place P2 on the stem end method

When ΔP is larger and P1 is larger, sealing P1 is obviously more difficult than sealing P2. Therefore, the method of changing the flow direction can be adopted, changing P1 at the stem end to P2 at the stem end, which is more effective for valves with high pressure and large pressure difference. For bellows valves, sealing P2 should usually be considered.