In addition to the general requirements for sealing material, the sealing ring should also pay attention to the following conditions:
(1) Flexibility and resilience;
(2) Appropriate mechanical strength, including expansion strength, elongation and tear strength.
(3) The performance is stable, it is not easy to swell in the medium, and the heat shrinkage effect (Joule effect) is small.
(4) Easy to process and maintain precise dimensions.
(5) Does not corrode the contact surface, does not contaminate the medium, etc.
The most suitable and most commonly used material to meet the above requirements is rubber, so the seals are mostly made of rubber. There are many varieties of rubber, and there are new varieties of rubber. When designing and selecting, you should understand the characteristics of various rubbers and make reasonable choices.