Main factors affecting valve sealing

1. Seal 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 pairs, so that the performance of the valve seal is reduced. Therefore, in the selection of seals, must choose the elastic deformation of the seal. At the same time, pay attention to the width of the sealing surface. The reason is that the contact surface of the sealing pair can not match completely. When the width of the sealing surface increases, the force required for sealing must be increased.

2. Specific pressure of sealing surface

The specific pressure of the sealing surface affects the sealing performance and service life of the valve. Therefore, the specific pressure of sealing surface is also a very important factor. Under the same conditions, too much 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. Genius valve

3. Physical properties of media

The physical properties of the medium also affect the sealing performance of the valve. These physical properties include temperature, viscosity and surface hydrophilicity. Temperature change not only affects the relaxation of sealing pair and the change of part size, but also has an inseparable relationship with gas viscosity. 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, we should design the sealing pair as the valve with thermal compensation such as elastic seat. The viscosity is related to the permeability of the fluid. Under the same conditions, the higher the viscosity, the smaller the permeability of the fluid. The hydrophilicity of the surface means that when there is a thin film on the metal surface, the film should be removed. Because of this thin oil film, the hydrophilicity of the surface will be destroyed, resulting in blockage of fluid channels.

4. Quality of sealing pair

The quality of sealing pair mainly refers to the selection of materials, matching and manufacturing accuracy. For example, the valve disc and seat sealing surface is very consistent, can improve the sealing. The characteristic of more circumferential waviness is that its labyrinth sealing performance is good.

Valve leakage is very common in daily life and production. In light, it will cause waste or bring danger to life. For example, the leakage of tap water valve will lead to serious consequences, such as the leakage of toxic, harmful, flammable, explosive and corrosive media in chemical industry, which will seriously threaten personal, property and environmental pollution.

A sealing device is designed for a valve which is driven by external force to open and close. It is used to install a certain number of packing rings in the packing culvert to achieve the sealing effect. But what is the sealing condition? The leakage at the packing of the valve is one of the parts of the valve which is easy to leak. However, there are two reasons for the leakage.