Classification and application of seals

In the field of sealing, we will divide the seals into two categories: dynamic seals and static seals according to the condition of the joint surface of the sealing parts. A seal in which the joint surfaces of the sealing parts move relative to each other is called a dynamic seal. Dynamic seals can be divided into two types: rotary seals and reciprocating seals, such as valve stems and stuffing boxes, screw rods of pumps, compressors and other equipment, and seals between rotating shafts or reciprocating rods and the body.

The joint surface of the sealing part and the static seal are called static seals, such as the seal between the flange joint surfaces of various containers, equipment and pipelines, the valve seat, valve body and the casing joint surface of various machines. There are three main types of static seals: gasket seals, glue seals and contact seals.

Static seals can also be divided into medium and low pressure static seals and high pressure static seals according to the working pressure. The medium and low pressure static seal is intended to be sealed with a gasket with a soft material and a wide contact surface, and a gold metal gasket with a hard material and a narrow contact width can be used for the high pressure static seal. Glue sealing is sealing with a material (sealant) that has bonding and sealing functions.

Static seals are generally contact-type seals, and dynamic seals are both contact-type and non-contact-type.