A, sealed classification

Seals can be divided into two categories: static seal between relatively static joint surfaces and dynamic seal between relatively moving joint surfaces. The sealing part of the static seal is static, such as pipe flange, thread connection, the seal between the pressure vessel and the cover, etc. The sealing part of the dynamic seal has relative motion, which can be divided into rotary seal and reciprocating seal, and can also be divided into contact seal and non-contact seal and shaftless seal.

 

1.1 Classification, characteristics and application of static seals

 

According to the working pressure, the static seal can be divided into medium, low pressure static seal and high pressure static seal. Medium and low pressure static seal commonly used soft material, gasket wide gasket seal, high pressure static seal with hard material, contact width is very narrow metal gasket.

 

According to the working principle, the static seal can be divided into flange connection gasket seal, self-tight seal, grinding surface seal, 0 ring seal, rubber ring seal, packing seal, thread connection gasket seal, thread connection seal, socket connection seal, sealant seal.

 

1.2 Classification, characteristics and application of dynamic seals

 

According to whether the sealing surface is sliding or rotating, dynamic seals can be divided into two basic types: reciprocating seals and rotary seals. According to whether the seal is in contact with the parts in relative motion, it can be divided into contact type, non-contact type and shaftless seal. Combined seal is the contact seal or non-contact seal several combination, in order to meet the higher sealing requirements. Generally speaking, the sealing surface of the contact seal is close to each other, contact, or even embedded, to reduce the gap or eliminate the gap to seal, so the sealing is good, but limited by friction and wear, suitable for sealing surface linear speed is low. The seals of the non-contact seal are not in direct contact, and there is a fixed assembly gap reserved, so there is no mechanical friction and wear. The seals have long working life, but the sealing is poor, and they are suitable for high speed occasions.