In any sealing structure, the rubber element installed in the sealing structure plays a major role. It is subjected to pressure, medium and temperature as well as various loads. However, the rubber element is in direct contact with other parts of the sealing structure. Therefore, whether they match properly in structure is related to the working ability of the whole system. Depending on the specific conditions of the application of the same rubber seal, the design of the mating parts should be treated differently and should not be jacketed. However, mechanical designers and editors who introduce sealing devices often neglect this point.
On the other hand, due to the lack of unification and standardization of materials and structural specifications, the types of seals are various, and the installation positions and service conditions of seals are also different, which makes the selection of seals difficult. One of the reasons for the lack of standardization is that seals are not easy to classify. It is necessary to define several important features for classification: function, structure, material, type of sealed medium, manufacturing method, etc.