Control valves play a very important role in automatic control of modern chemical plants. The production of these plants depends on the correct distribution and control of the flowing medium. These controls, whether the exchange of energy, the reduction of pressure, or the simple container feeding, require some final control elements to complete.

Belongs to the valve control valve, the main role is to adjust the parameters of the medium pressure, flow rate, temperature and so on, is the final process control elements in the loop. How to solve the problem of leakage of electric regulating valve

) 1 increase in seal oil method

Of electric control valve of unused oil seal, consider increasing the seal fat to improve the performance of stem seal.

2) increase the packing method

To improve the packing of the valve stem sealing performance, can be used to increase packing method. It is usually used in the form of double layer and multi-layer mixed packing, which increases the quantity simply, such as adding 3 pieces to 5 pieces, and the effect is not obvious.

3) the replacement of graphite packing method

The extensive use of PTFE packing, its operating temperature range of -20 to 200 DEG C, when the temperature in the upper and lower limits, change is large, the seal will be significantly decreased, aging fast, short life. Flexible graphite filler can overcome these shortcomings and have long service life. Therefore, some factories have changed the fillers of tetrafluoroethylene into graphite filler, and even the newly bought adjustment valves also replace the tetrafluoro fillers into graphite fillers. However, the use of graphite filler has a large back difference and some creeping phenomena at the beginning, which must be considered.

4) a change in the flow, put the P2 in the stem end method

When P is large, P1 and P1 than the larger, seal seal P2 difficult. Therefore, can be used to change the flow of the P1 to P2 in the stem end of the stem end, which is high pressure, great pressure valve is more effective. Such as bellows valve should normally be considered seal P2.

5) using lens pad seal method

For the upper and lower lid seal, the sealing seat and the upper and lower body. If it is a plane sealing under high temperature and pressure, the sealing is poor, causing leaks, you can use the lens pad seal, to get satisfactory results.

6) replacement gasket

So far, most still use asbestos gasket under high temperature, poor sealing performance, life expectancy is short, causing leaks. In this case, the winding gasket, the "O" ring, and so on, are now used in many factories.