There are many factors affecting valve sealing, mainly including the following:

 

1. The structure of the sealing pair will change under the change of temperature or sealing force effect. And this change will affect and change the effect force between the sealing pair, thereby reducing the performance of the valve seal. Therefore, when choosing a seal, it is necessary to choose a seal with elastic deformation. At the same time, also pay attention to the width of the sealing surface. The reason is that the contact surface of the sealing pair cannot be completely matched. When the width of the sealing surface is increased, the effect force required by the sealing must be increased.

 

2. The specific pressure of the sealing surface The specific pressure of the sealing surface affects the sealing function of the valve and the service life of the valve. Therefore, the specific pressure of the sealing surface is also a very important factor. Under the same conditions, too high specific pressure will cause valve damage, but too low specific pressure will cause valve leakage. Therefore, we need to fully consider the appropriateness of the specific pressure when planning.

 

3. The physical properties of the medium The physical properties of the medium also affect the valve sealing function. These physical properties include temperature, viscosity, and hydrophilicity of the surface, among others. The temperature change not only affects the slackness of the sealing pair and the change of the standard of the parts, but also has an inseparable relationship with the viscosity of the gas. Gas viscosity increases or decreases with increasing or decreasing temperature. Therefore, in order to reduce the influence of temperature on the sealing function of the valve, when we design the sealing pair, we should design it as a valve with thermal compensation such as an elastic valve seat. Viscosity is related to the penetrating ability of the fluid. When under the same conditions, the higher the viscosity, the lower the penetration capacity of the fluid. The hydrophilicity of the surface means that when there is a film on the metal surface, the film should be removed. Because of this thin oil film, it will destroy the hydrophilicity of the surface, resulting in blocking the passage of fluid.

 

4. The quality of the sealing pair The quality of the sealing pair mainly means that we must check the selection, matching and manufacturing accuracy of materials. For example, the disc and the sealing surface of the valve seat are very consistent, which can improve the sealing performance. The characteristic of the large circumferential waviness is its good labyrinth sealing function.