The sealing surface is the most critical part of the valve. The quality of the sealing surface 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.
Therefore, the following factors should be considered when selecting the valve sealing surface material:
①Corrosion resistance.
“Corrosion” refers to the process in which the sealing surface is damaged by the medium.
If the surface is damaged in this way, the sealing performance cannot be guaranteed.Therefore, the sealing surface material must be corrosion resistant.
②Anti-abrasion.
“Scratch” refers to the damage caused by friction of the material during the relative movement of the sealing surface.
This kind of damage will inevitably cause damage to the sealing surface. Therefore, the sealing surface material must have good scratch resistance, especially for gate valves.
③Erosion resistant.
“Erosion” refers to the process of destroying the sealing surface when the medium flows through the sealing surface at high speed.
This kind of damage is more obvious in the throttle valve and safety valve used in the high temperature and high pressure steam medium, which has a great impact on the sealing damage.
④ There should be a certain degree of hardness, and the hardness will drop greatly under the specified working temperature.
⑤ The linear expansion coefficient of the sealing surface and the body material should be similar, which is more important for the structure of the inlaid sealing ring, so as to avoid excessive stress and loosening at high temperatures.
⑥Used under high temperature conditions, there must be sufficient anti-oxidation, thermal fatigue resistance and thermal cycling.
