Sealing is to prevent leakage, and the principle of valve sealing is also studied from leakage prevention. There are many factors that affect the sealing performance of butterfly valves, mainly including the following:
1. Sealing structure
Under the change of temperature or sealing force, the structure of the sealing pair will change. Moreover, this change will affect and change the force between the sealing pairs, thereby reducing the performance of the valve sealing. Therefore, when choosing a seal, be sure to choose a seal with elastic deformation. At the same time, also pay attention to the thickness of the sealing surface. The reason is that the contact surface of the sealing pair cannot be completely matched. When the width of the contact surface of the sealing surface increases, the force required for sealing is increased.
2. Specific pressure of sealing surface
The specific pressure of the sealing surface affects the sealing performance of the butterfly 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 small specific pressure will cause valve leakage. 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 butterfly valve. 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 size 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 performance of the valve, when designing the sealing pair, we should design it as a valve with thermal compensation such as an elastic valve seat. Viscosity is related to the permeability of the fluid. When under the same conditions, the greater the viscosity, the less the penetrating ability 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 very thin oil film, it will destroy the hydrophilicity of the surface, resulting in blockage of fluid channels.
4. Quality of 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 valve disc fits well with the valve seat sealing surface, which can improve the sealing performance.
Valve leakage is very common in life and production, which can cause waste or bring danger to life, such as leakage of tap water valves, and serious consequences, such as toxic, harmful, flammable, explosive and The leakage of corrosive media, etc., is a serious threat to personal safety, property safety and environmental pollution accidents. Choose suitable seals according to different environments and use characteristics.
Post time: Aug-01-2022
