• Main Factors Affecting the Sealing of the Valve

Main Factors Affecting the Sealing of the Valve

The following are the main factors affecting the sealing of the valve.
 

The sealing pair structure

With the change of temperature or sealing force, the structure of the sealing pair will change, which will affect and change the force between the sealing pairs, thus impairing the sealing of the valve.

It is necessary to choose seals with elastic deformation. At the same time, pay attention to the width of the sealing surface. The reason is that the contact surfaces of the sealing pair cannot be completely matched, and the force required for sealing should be increased when the width of the sealing surface increases.


The specific pressure of the sealing surface

The specific pressure of the sealing surface affects the sealing and service life of the valve. Under the same conditions, if the specific pressure is too high, the valve will be damaged, but if the specific pressure is too low, the valve will leak. Therefore, the suitability of the specific pressure should be fully considered during valve design.

Physical properties of the medium

The physical properties of the medium also affect the sealing of the valve. These physical properties include temperature, viscosity and surface hydrophilicity.
 
Temperature change not only influences the  looseness of the sealing pair and the change of the part size, but also has an inextricable connection with the viscosity of gas, which increases or decreases with the increase or decrease of the temperature.

Viscosity is related to the permeability of fluid. Under the same conditions, the greater the viscosity is, the smaller the permeability of fluid will be.
 
Surface hydrophilicity means that when there is a thin film on the metal surface, the thin film should be removed, otherwise the hydrophilicity of the surface will be damaged, causing the fluid passage to be blocked.


The quality of the sealing pair
 
The quality of the sealing pair means that attention should be paid to the selection, matching and manufacturing accuracy of materials. For example, the disc fits well with the sealing surface of the seat, which can improve the sealing of the valve.
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