When selecting the material of the O-ring, the compatibility with the working medium must be considered first, and then the pressure, temperature, continuous working time and other conditions of the seal must be comprehensively considered. Although the performance of the material can directly affect the performance of the O-ring, in addition to the general requirements of the sealing ring material, the O-ring should also pay attention to the following conditions:

1. It is elastic and resilient.

2. Appropriate mechanical strength, including expansion strength, elongation and tear strength.

3. Stable performance, not easy to swell in the medium, and small thermal shrinkage effect.

4.it is easy to process and form, and can maintain precise dimensions.

5.does not corrode the contact surface, does not pollute the medium, etc.

The most suitable and most commonly used material to meet the above requirements is rubber, so O-rings are mostly made of rubber materials. There are many varieties of rubber, and new varieties of rubber appear constantly. When designing and selecting, you should understand the characteristics of various rubbers and choose them reasonably.