Technical Articles

Six Important Factors of Selecting the Valve Sealing Surface Material

Sealing surface is the most critical face of the valve, so the quality of the sealing surface directly affects the service life of the valve, and the material of the sealing surface is an important factor to ensure the quality of the sealing surface. Therefore, the choice of valve sealing surface material should consider the following factors：

1. Corrosion Resistance: Corrosion refers to the process of the sealing surface damaged under the action of the medium. If the surface suffered this kind of damage, and the seal ability can not be guaranteed, therefore, the sealing surface material must be resistant to corrosion. The corrosion resistance of the material depends mainly on the composition of the material and its chemical stability.

2. Anti-bruise: Bruise refers to the damage caused by the friction material under the process of the relative movement between the sealing surfaces. This kind of damage will inevitably lead to the damage of the sealing surface, therefore, the sealing surface material must have good anti-bruise performance, especially the gate valve. The anti-bruise performance of the material is often determined by the internal nature of the material.3. Erosion Resistance: Erosion refers to the process of the sealing surface damaging caused by the medium pass the sealing surface as a high-speed flow. This kind of damage is more obvious in the the throttle, safety valve used in the high temperature, high pressure steam medium,because there is the great impact on the sealing damage. So, erosion resistance is also one of the important requirements of the sealing surface material.

4. The material of the sealing surface should have a certain hardness, and a large drop couldn’t occur at a predetermined working temperature hardness

5. The linear expansion coefficient of the sealing surface material should be similar to the raw material, and this is more important to the structure of the seal ring to avoid the additional stress at high temperatures and loosening.

6. The sealing surface material should have the ability of antioxidant and the thermal fatigue resistance under the high temperature.

At present, it is difficult to find a sealing surface material that fully meets the above requirements. It could only be based on different valves and uses, focusing on a number of aspects to meet the requirements. For example, the valves used in high-speed media should pay attention to the erosion requirements of the sealing surface, and it should choose a higher hardness of the sealing material when the media contains solid impurities.

DBV VALVE GROUP established in 2001，specialized in ball valve and butterfly valve manufacturing.