Static seal. According to the working pressure, the static seal can be divided into middle and low pressure static seal and high pressure static seal. Medium and low pressure static seal is usually made of soft gasket with wide gasket, while high pressure static seal is made of hard metal gasket with narrow contact width.
Dynamic seal. It can be divided into contact seal and non-contact seal according to whether the seal is in contact with the zero degree part of its relative movement.
Generally speaking, contact seal has good sealing performance, but it is limited by friction and wear, so it is suitable for the occasion with low sealing surface line. According to the contact position of the seal, the contact seal can be divided into circular (radial) seal and end face seal. Face seal is also called mechanical seal. The non-contact dynamic seal includes labyrinth seal, power seal, etc.
The former is to use the throttling effect of fluid between gaps to limit leakage, with a large amount of leakage, which is usually used in the sealing between stages and other occasions with low requirements. The power seal includes centrifugal seal, floating ring seal and spiral seal. It uses the pressure head generated by the power components to offset the pressure difference between the two sides of the seal to overcome the leakage. It has a high sealing performance, but it consumes a lot of energy, and it is difficult to obtain the high pressure head. Non contact seal, because the sealing surface is not directly contacted, the starting power is small and the service life is long.
