The Sealing Principle Of Rubber Seals

The sealing material is not only rubber, but also graphite and metal (mechanical seal). Depending on the type of sealing device, the sealing effect of rubber seals is not exactly the same. But no matter what type of sealing device, the unique elasticity and resilience of rubber are used for sealing, which is basically similar. Therefore, rubber seals are particularly useful in fluid sealing.

The rubber seal should be installed into the groove in an extended state, and it will be subject to large elastic deformation (interference) after assembly, so that the sealing cavity relies on the resilience of the rubber seal to generate the allowable sealing force within the tolerance range. . The elastic deformation of rubber enables it to maintain its tightness under different motion states, even when the running surface is not concentric, which is a large deformation under low stress.

Due to the high Poisson ratio of rubber, under the applied axial fluid pressure, the rubber seal can automatically appear a radial sealing force proportional to it (the volume remains basically unchanged before and after deformation). As a result, rubber seals can be successfully installed in relatively simple, inaccurate sealing cavities, and have wider tolerances than other sealing materials.

The fundamental reason why rubber seals can automatically activate energy under the pressure of sealing fluid is the elasticity and resilience of rubber. Whether it is static sealing or dynamic sealing, this valuable characteristic of rubber is inseparable.