Flange gasket. A gasket is a circular ring made of a material that can produce plastic deformation and has a certain strength. Most gaskets are cut from non-metallic plates or made by professional factories according to specified scales, and their materials are asbestos rubber sheets, asbestos sheets, PTFE sheets, polyethylene sheets, etc.
A metal gasket made by wrapping non-metallic materials such as asbestos with thin metal plates (such as white iron sheet and stainless steel); There is also a type of wrap around gasket made of thin steel strip and asbestos strip, the most commonly used being a metal wrap gasket made of stainless steel strip and graphite. Depending on the application environment, the wrap around gasket can also be made of asbestos.
General rubber gaskets are suitable for applications with temperatures below 120 ℃; Asbestos rubber gaskets are suitable for situations where water vapor temperature is below 450 ℃, oil temperature is below 350 ℃, and pressure is below 5MPa. For general corrosive media, the most commonly used is acid resistant asbestos board. In high-pressure equipment and pipelines, use lens shaped or other shaped metal gaskets made of copper, aluminum, No. 10 steel, or stainless steel.
The touch width between the high-pressure gasket and the sealing surface is very narrow (line touch), and the machining smoothness between the sealing surface and the gasket is high. Low pressure small diameter threaded flanges are used, while high pressure and low pressure large diameter welded flanges are used. The thickness of flange plates and the diameter and quantity of connecting bolts vary with different pressures.