The difference between dynamic seal and static seal of O-ring

Static seal. According to the working pressure, static seals can be divided into medium and low pressure static seals and high pressure static seals. The medium and low pressure static seals usually use softer materials and wider gaskets, while high pressure static seals use metal gaskets with hard materials and narrow contact widths.

Dynamic seal. According to whether the seal is in contact with the zero-degree parts that move relative to it, it can be divided into contact seals and non-contact seals.

Generally speaking, the sealing performance of the contact seal is good, but it is limited by friction and wear, so it is suitable for occasions where the sealing surface line is low. In the contact seal, it can be divided into circumferential (radial) seal and end face seal according to the contact position of the seal. Face seals are also known as mechanical seals. Non-contact dynamic seals include labyrinth seals and dynamic seals.

The former is to use the throttling effect of the fluid between the gaps to limit leakage, and the leakage is large, and it is usually used for sealing between stages and other occasions; Dynamic seals include centrifugal seals, floating ring seals, spiral seals, etc. It relies on the pressure head generated by the power element to offset the pressure difference on both sides of the seal to overcome leakage. It has high sealing performance, but it consumes a lot of energy and is difficult to obtain high pressure head. Non-contact sealing, since the sealing surface is not in direct contact, the starting power is small and the service life is long.