In the process of daily inspection, sealed pressure devices such as boilers, pressure vessels, and pressure pipelines can not be separated from the silicone rubber gaskets. However, because most people lack professional knowledge in the selection and application scope of silicone rubber gaskets, they only choose by experience, which is bound to produce some misunderstandings. So the running, taking, dripping, and leakage phenomenon is common, causing a lot of waste to the unit, and even due to the failure of the silicone gasket caused by serious accidents. These situations are mainly due to the selection and assembly of the silicone gasket. Given the above situations, it is necessary to make a specific introduction to the selection of silicone rubber gasket.

How Silicone Gasket is Made and What Factors Can Make Influence?

The role of a silicone gasket is to prevent the leakage of the sealed medium, and the form of leakage can be divided into interface leakage and penetration leakage. The cause of interface leakage is usually due to the relaxation of the pressing force between the sealing surface, aging, deformation, corrosion, wear or burn of the sealing surface, and mechanical vibration under working conditions. The infiltration leakage is related to the material type of silicone gasket, the manufacturing method, the nature of the sealed medium, and the working pressure, temperature, and other factors.

Theoretically speaking, even if the silicone gasket is used, it is impossible to achieve complete contact between the sealing surface, so that there is no microscopic channel or gap. Although these channels are extremely small, the molecular volume of the fluid medium is still large enough, so it is impossible to prevent the fluid completely at the edge of the sealing surface. There is always a part of the fluid entering the sealed contact between the surface, and there is a complex hydrodynamic and thermodynamic process. It is generally believed that after the fluid enters the extremely small and irregular gaps between the sealing surface, it will generate resistance loss in the flow process to consume its energy. At the same time, the static boundary layer will be generated on the wall of these gaps, which will make the small channel become more narrow or even completely blocked so that the fluid entering the sealing surface can not continue to flow, to realize the sealing.

The factors that affect sealing mainly include the following situations:

  • The surface condition of the sealing surface;
  • The level of contact width of the sealing surface;
  • The nature of the fluid;
  • The temperature of the fluid;
  • The material of the silicone gasket;
  • The pre-tightening force applied on the sealing surface;
  • The influence of other external conditions (mainly the vibration of the system, deformation of the connector, installation position deviation, etc.).

 If the seal is reliable, the above factors must be seriously considered, and the quality and selection of silicone gasket are also crucial.

silicone rubber seal

How To Choose Silicone Gasket?

custom silicone seal

There are several factors you need to consider when you want to choose silicone gaskets for your devices.

  • The properties of the fluid, that is, the physical and chemical properties of the fluid medium in contact, will react with the gasket.
  • The pressure of the fluid, that is, the pressure of the fluid medium, is positive or negative, the maximum working pressure, and whether there are pressure pulsations and other factors.
  • The temperature of the fluid, that is, the temperature of the fluid medium, and whether there are temperature changes during operation.

What Is The Assembly of Silicone Gasket?

The assembly of silicone gaskets is a key factor in practical application. General requirements for assembly have the following aspects.