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What is the cause of the valve's loose sealing?

Posted by Bundor valve
Leakage at the valve seal is a part of the valve that is prone to leak failures. The reasons of the valve is not tightly sealed are probably as follows.
1.Seal sub structure
Under the change of temperature or sealing force, the structure of the sealing pair will change. And this change will affect and change the mutual force of the sealing pair, so that the performance of the valve seal is reduced. Therefore, when choosing a seal, it is necessary to select 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. When the width of the sealing face 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 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, excessive specific pressure will cause damage to the valve, but if the specific pressure is too small, the valve will leak. Therefore, we need to fully consider the appropriateness of the specific pressure when designing.
3. Physical properties of the 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 looseness of the seal pair and changes in the size of the part, but also has an inseparable relationship with the viscosity of the gas. The gas viscosity increases or decreases with increasing or decreasing the temperature. Therefore, in order to reduce the influence of temperature on the sealing performance of the valve, we should design the sealing pair as a valve with thermal compensation such as elastic seat. Viscosity is related to the permeability of the fluid. When under the same conditions, the greater the viscosity, the less the fluid's permeability. Surface hydrophilicity means that when there is a thin film on the metal surface, this thin film must be removed. Because this thin layer of oil film will destroy the hydrophilicity of the surface and cause the passage of fluid.
4.The quality of the sealing pair
The quality of the sealing pair mainly means that we have to check the selection, matching and manufacturing accuracy of materials. For example, the sealing surface of valve disc and valve seat is very consistent, which can improve the sealing performance. The characteristic of more circumferential waviness is the good performance of labyrinth seal. The characteristic of more circumferential waviness is the good performance of labyrinth seal.
The above is the entire content of the reasons for the lax valve sealing introduced for you. If you have any questions, you can click the website online customer service for consultation.