A plug valve is a valve that uses a plug body with a hole as the opening and closing part and realizes the opening and closing action through the rotation of the plug body and the valve stem. The plug valve is simple in structure, quick in opening and closing, and small in fluid resistance. In recent years, as one of the earliest valves adopted by people in history, it has not been replaced by new valves such as ball valves, but the market has become more and more popular.

There are two basic series of plug valves:

1. X43F type: sealing pair composed of specially designed valve seat bushing (PTFE or para polyphenylene) and steel plug body; The plug body is stainless steel (not lined).

2. X43F46 type: FEP is lined on the surface of all valve bodies and plug passages. As well as the lining PFA, PCTFE and ppl with the temperature up to 300℃ expanded according to the above basic form, which are new materials for inlaying the valve seat to meet the needs of various working conditions. X43F and X43F46 self-lubricating plug valves have unique rocker arm adjusting device and ideal plug cone angle design, good sealing performance, long service life, and the advantages of simultaneous sealing at the inlet and outlet ends. During the whole working process, the friction coefficient of the sealing pair is small, and the plug body is flexible and never needs lubrication.

Structural features of X43F plug valve

1. The inlet and outlet windows of the valve body are designed with a double groove seal ring structure. During the rotation of the cock, the seal specific pressure between its seal pairs gradually changes until it reaches the fully open or fully closed position, generating sufficient seal specific pressure and achieving zero leakage of the seal pair.

2. The double groove seal ring can not only make the PTFE bushing stably displace inside the valve body, but also absorb the slight deformation of the bushing caused by the temperature difference change. At the same time, the bushing and the plug have a strong wiping effect, which improves the service life of the sealing surface.

3. The upper part of the plug shaft is composed of a PTFE diaphragm, an O-ring and an adjusting gasket, which can not only adjust the sealing specific pressure between the sealing surfaces, make the plug rotate flexibly, but also ensure the sealing of the inlet and outlet ends and the connecting end of the middle flange.

4. The whole sealing process can be approximately considered independent of the pressure in the pipeline.

5. The PTFE bushing is filled with different materials according to the service temperature and working medium, which has good lubrication and long service life.