The sealing surface is the most critical working surface of the valve; the quality of sealing surfaces directly affects the service life of the valve; the material of the sealing surface is an important factor to ensure the quality of the sealing surface. The following factors should be considered during the selection of valve sealing surface materials.
1. Corrosion resistance
The corrosion of the sealing surface means the process that the sealing surface is damaged with the action of the medium. If the surface is damaged in this way, the sealing of the valve cannot be guaranteed. Thus, the materials of the sealing surface must be corrosion resistant. The corrosion resistance of materials mainly depends on their composition and chemical stability.
2. Scratch resistance
The scratch of the sealing surface means the damage of the sealing surface material caused by friction during the relative motion of sealing surfaces. Therefore, the material of the sealing surface must have good scratch resistance, especially the sealing surface material of gate valve. The scratch resistance of materials is often determined by their internal properties.
3. Erosion resistance
The erosion of the sealing surface refers to the process that the sealing surface is damaged by the fast flowing medium. Erosion resistance is also one of the important factors to pick sealing surface materials.
The material of the sealing surface should have a certain hardness.
At present, it is very difficult to find sealing surface materials that fully meet the above requirements, and the materials can only meet certain requirements according to different types and uses of valves. For example, if the valve is used for transporting fast flowing media, the valve sealing surface should be erosion resistant. If the medium contains solid impurities