Six Solutions to Solve Leakage of Electric Regulating Valve
Electric regulating valve is an important unit in the process of industrial automation. With the increasing degree of automation in industrial field, it is being used more widely in various fields of commercial production. However, it happens often that leakage is found when using regulating valve, how can we deal with it?
1. Increase the sealing grease
Valves that do not use sealing grease are proposed to add some grease to improve the sealing performance of stem.
2. Increase packing
To improve the sealing performance of packing acting on stem, it is usually adopted that applying double-layer or multi-layer mixed packing on stem, but not simply increasing its number, such as adding 3 pieces to 5 pieces.
3. Change graphite packing
The extensive used packing material of PTFE-its sealing properties will be significantly decreased with aging fast and short life, when the temperature changes in the upper and lower limits of 20 to 200℃, while flexible graphite packing overcomes these shortcomings. As a result, some factories changed PTFE into flexible graphite packing, even the new purchase of regulating valves.
4. Turn the flow direction and place P2 at the stem end
It is obvious that sealing P1 is more difficult than sealing P2 when P1>P2 and ΔP is large, thus changing flow direction can be helpful. Placing P2 at the end of stem instead of P1 can be effective to high pressure and large ΔP valve, such as bellows valves should generally seal P2.
5. Seal with lens ring
For seal between the top and bottom bonnet or cover and seal between seat and body, sealing with lens ring can solve problems when leakage happens in plane seal at high temperature and pressure.
6. Replace the gasket
So far, most gasket is still asbestos board. This material is of poor sealing performance and short life at high temperature and will cause leakage. In this case, winding gasket like O-ring has been widely used in many factories.
Source: China Valves Manufacturer – Yaang Pipe Industry (www.ugsteelmill.com)