Author:Site Editor Publish Time: 2019-05-01 Origin:Site
In the use of electric industrial butterfly valve, the use environment is often damaged due to leakage problems, so preventing leakage is an important problem that needs to be solved by electric butterfly valves. Introduce several methods that can effectively solve the leakage of electric butterfly valves.
Increase seal grease method
For valves that do not use seal grease, consider adding seal grease to improve stem seal performance.
Add filler method
In order to improve the sealing performance of the filler to the valve stem, a method of increasing the filler may be employed. Usually, it is a double-layered, multi-layered mixed filler form, which simply increases the number. For example, if you increase 3 pieces to 5 pieces, the effect is not obvious.
Replacement of graphite filler
The PTFE filler used in large quantities has a working temperature of -20 to +200 ° C. When the temperature is higher at the upper and lower limits, the sealing property is significantly reduced, the aging is fast, and the life is short. Flexible graphite fillers overcome these shortcomings and have a long service life. Therefore, some factories have changed the PTFE filler to graphite filler, and even the newly purchased regulator valve has replaced the PTFE filler with graphite filler. However, the use of graphite fillers has a large difference in backlash, and some of them also have creeping phenomena at the beginning, which must be considered.
Change the flow direction, set P2 at the stem end
When ΔP is larger and P1 is larger, the seal P1 is obviously more difficult than the seal P2. Therefore, the method of changing the flow direction can be adopted, and the P1 is changed to the P2 end at the valve stem end, which is high in pressure and pressure difference. Large industrial valves are more effective. For bellows valves, seal P2 should normally be considered.
Lens pad sealing method
For the sealing of the upper and lower covers, the valve seat is sealed with the upper and lower valve bodies. If it is a flat seal, under high temperature and high pressure, the sealing performance is poor, causing leakage, and the lens pad seal can be used instead, and satisfactory results can be obtained.
Replace the gasket
Up to now, most of the sealing gaskets still use asbestos sheets. At high temperatures, the sealing performance is poor and the service life is short, causing leakage. In this case, you can use a wound gasket, an "O" ring, etc., which is now used in many factories.