1. Sealing pair structure
Under the change of temperature or sealing force, the structure of sealing pair will change. And this change will affect and change the force between the sealing pair, thus reducing the performance of the valve seal. Therefore, in the selection of seals, we must choose seals 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 surface can not completely kiss the platform, when the width of the sealing surface increases, it is necessary to increase the force required for sealing.
2. Specific pressure of sealing surface
The specific pressure of the sealing surface affects the sealing performance of the valve and the service life of the valve. Therefore, the sealing surface pressure 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 suitability of specific pressure in the design.
3. Physical properties of medium
The physical properties of the medium also affect the sealing performance of the valve. These physical properties include temperature, viscosity and surface hydrophilicity. The change of temperature not only affects the relaxation of sealing force and the change of part size, but also has an inseparable relationship with the viscosity of gas. The gas viscosity increases or decreases with the increase or decrease of temperature. Therefore, in order to reduce the influence of temperature on the sealing performance of the valve, when we design the sealing pair, we should design it as a valve with thermal compensation such as elastic seat. Viscosity is related to the permeability of the fluid. Under the same conditions, the greater the viscosity, the smaller the permeability of the fluid. Hydrophilicity of the surface means that when there is a film on the metal surface, the film should be removed. Because this very thin oil film will destroy the hydrophilicity of the surface and lead to the formation of the film
It can block the passage of fluid.
4. Quality of sealing pair
The quality of sealing pair mainly means that we should check the material selection, matching and manufacturing accuracy. For example, the disc and seat sealing surface is very consistent, can improve the sealing. Its labyrinth sealing performance is good because of its more circumferential waviness.
Post time: Mar-07-2022