The gasket is a ring made of a material that produces plastic deformation and has a certain strength. Most gaskets are cut from non-metal plates or manufactured by professional factories according to the required size. The materials are asbestos rubber plate, asbestos plate, PTFE plate, polyethylene plate, etc.; also use thin metal plate (tin plate, (Stainless steel) Metal-clad gaskets made of non-metallic materials such as asbestos; there is also a wound gasket made by winding thin steel strips with asbestos belts, the most commonly used being stainless steel belts and graphite wounds. The metal spiral wound gaskets can also be made of asbestos depending on the use environment. Ordinary rubber gaskets are suitable for applications where the temperature is lower than 120°C; asbestos rubber gaskets are suitable for applications where the water vapor temperature is lower than 450°C, the oil temperature is lower than 350°C, and the pressure is lower than 5MPa. Medium, the most commonly used acid-resistant asbestos board. In high-voltage equipment and pipelines, lens-type or other-shaped metal gaskets made of copper, aluminum, No. 10 steel, and stainless steel are used. The contact width of the high-pressure gasket and the sealing surface is very narrow (line contact), and the sealing surface and the gasket have a high processing finish.