What material is used to seal the contact part between the valve stem and the valve body of the pneumatic plug valve

The commonly used sealing materials for the contact part between the valve stem and valve body of pneumatic plug valves include asbestos, polytetrafluoroethylene (PTFE) fibers, etc. This type of material has good corrosion resistance (based on actual reports) and low friction coefficient, which can prevent medium leakage.

Specifically, fillers are generally woven from materials such as asbestos and polytetrafluoroethylene fibers. When the valve stem moves up and down, the packing will be squeezed into the space between the valve stem and the packing box. For example, PTFE fiber woven fillers have low friction coefficients and good corrosion resistance (based on actual reports). By tightening the packing gland, the packing can be in close contact with the valve stem, preventing the medium from leaking along the valve stem. In addition, the packing can adapt to the slight swing and wear of the valve stem to a certain extent, maintaining sealing.

In practical applications, the sealing methods of pneumatic plug valves also include auxiliary means such as rubber sealing rings and grease seals. Rubber sealing rings have good elasticity and performance, and can adapt to the degree of unevenness of the sealing surface and slight deformation of the gate plate, protecting the excellent sealing performance. Oil seal is suitable for special working conditions with high temperature or corrosive media. It can form a protective film around the sealing surface, reduce friction, and extend the service life of the seal.