Selection and requirements of sealing materials

Introduce the selection and requirements of sealing materials.
The sealing material shall meet the requirements of sealing function. Due to different sealed media and different working conditions of equipment, sealing materials are required to have different adaptability. The general requirements for sealing materials are:
1) The material has good compactness and is not easy to leak media;
2) Have appropriate mechanical strength and hardness;
3) Good compressibility and resilience, small permanent deformation;
4) No softening and decomposition at high temperature, no hardening and embrittlement at low temperature;
5) Good corrosion resistance, can work for a long time in acid, alkali, oil and other media, its volume and hardness change little, and does not adhere to the metal surface;
6) Low friction coefficient and good wear resistance;
7) It has softness combined with the sealing surface;
8) Good aging resistance and durability;
9) It is easy to manufacture, cheap and easy to obtain materials.
Rubber is the most commonly used sealing material. In addition to rubber, graphite, PTFE and various sealants are suitable for sealing materials.