There are three types of high-pressure flange sealing surface: plane sealing surface, suitable for low pressure, non-toxic media occasions; Concave and convex sealing surface, suitable for slightly higher pressure occasions; Tenon groove sealing surface, suitable for flammable, explosive, toxic medium and high pressure occasions.
The contact width of high-pressure flange gasket and sealing surface is very narrow (line contact), and the processing finish of sealing surface and gasket is high. Common integral flange has flat welding flange and butt welding flange. Ordinary rubber gasket is suitable for the occasion of temperature below 120℃; Asbestos rubber gasket is suitable for water vapor temperature is less than 450℃, oil temperature is less than 350℃, pressure is less than 5MPa occasions, for the general corrosive medium, the most commonly used is acid resistant asbestos plate.

Low pressure small diameter threaded flange, high pressure and low pressure large diameter are welded flange, flange thickness and connecting bolt diameter and number of different pressure is different.
Most of the gaskets are cut down from non-metallic plates, or made by professional factories in accordance with the specified size, its materials are asbestos rubber sheets, asbestos sheets, polyethylene sheets, etc. Also useful thin metal plate (iron sheet, stainless steel) asbestos and other non-metallic materials wrapped up made of metal gasket; There is also a winding gasket made of thin steel tape and asbestos tape wound together.
High pressure flange connection is a detachable connection. According to the connected parts can be divided into container flange and pipe flange. According to the structure, there are integral flanges, looping flanges and threaded flanges.
In high pressure equipment and pipelines, the use of copper, aluminum, no. 10 steel, stainless steel made of lens type or other shape of metal gaskets. The rigidity of high pressure flange is poor, suitable for pressure P ≤4MPa occasions; High pressure flange, also known as high neck flange, is more rigid, suitable for high pressure and temperature occasions. High pressure flange gasket is a kind of ring which can produce plastic deformation and has a certain strength.