High-pressure ball valve performance lies in the ball, the seat surface hardening treatment. In order to ensure the metal to metal seal, high pressure ball valve seat seal than the pressure is much larger than the normal ball valve, which makes the metal material prone to bite or strain, both cases will directly lead to the ball valve can not be used normally.
In order to reduce and eliminate the occlusion of the ball valve seat, strain. Then, we must adopt a special approach, the process of ball seat surface hardening.
Currently the most widely used, the best ball seat surface hardening method is spraying cemented carbide, high pressure ball valve ball seat and spray coating to a large extent determines the ball seat sealing performance and life.
Carbide with a high hardness, wear resistance, good strength and toughness, heat resistance, corrosion resistance and a series of excellent performance, especially its high hardness and wear resistance, even at temperatures of 500 ℃ also remained unchanged , Still have very high hardness at 1000 ℃. Therefore, and its use and high pressure ball valve used in the environment of high temperature and pressure requirements.
The choice of cemented carbide layer mainly depends on:
1, the hardness, erosion resistance, hard solid particle media conditions have requirements. Such as coal chemical industry, polysilicon industry;
2, Corrosion resistance medium conditions have requirements. Such as petrochemical, paper industry.