The flange is the part that connects the pipe to the pipe and is connected to the pipe end. There are holes on the flanges, and bolts connect the two flanges tightly. The flanges are sealed with gaskets. Flanged pipe fittings (flanged pipe fittings) refer to pipe fittings with flanges (flanges or flanges). It can be cast, threaded or welded. Flange connection (flange, joint) consists of a pair of flanges, a gasket and several bolts and nuts. The gasket is placed between the sealing surfaces of the two flanges. After tightening the nut, the specific pressure on the contact surface of the gasket will deform when it reaches a certain value, and fill the unevenness on the sealing surface to make the connection tight and leak-proof. Flange connection is a detachable connection. According to the connected parts, it can be divided into container flange and pipe flange. According to the structure type, there are integral flanges, looper flanges and threaded flanges. Commonly used integral flanges include flat welding flanges and butt welding flanges. The rigidity of the flat welding flange is not good, and it is suitable for occasions where the pressure is p≤4MPa; the butt welding flange, also known as the high-neck flange, has a relatively large rigidity and is suitable for occasions with high pressure and temperature. There are three types of flange sealing surfaces: flat sealing surface, suitable for occasions where the pressure is not high and the medium is non-toxic; concave and convex sealing surface, suitable for occasions with slightly higher pressure; tongue and groove sealing surface, suitable for flammable, explosive, toxic Medium and high pressure occasions.
A gasket is a ring made of a material that can produce plastic deformation and has a certain compressive strength. Most gaskets are cut from non-metallic plates, or made by professional factories according to standard sizes. The materials are asbestos rubber sheets, asbestos sheets, polyethylene sheets, etc.; Metal clad gaskets made of non-metallic materials such as wrapping; there is also a spiral wound gasket made of thin steel strips and asbestos strips. Ordinary rubber gaskets are suitable for occasions where the temperature is lower than 120 °C: asbestos rubber gaskets are suitable for applications where the temperature of water vapor is lower than 450 °C, the temperature of oil is not more than 350 °C, and the pressure is not more than 5MPa. For general corrosive media, The most commonly used is acid-resistant asbestos board. In high-pressure equipment and pipelines, choose lens-type or other-shaped metal gaskets made of copper, aluminum, 10-gauge steel, and stainless steel. The contact width between the high-pressure gasket and the sealing surface is very narrow (line contact), and the processing smoothness of the sealing surface and the gasket is high.
Common pressure grades: 10K, 20K flange connection type plate type flat welding flange with neck flat welding flange with neck butt welding flange socket welding flange threaded flange flange cover with neck butt welding ring loose sleeve flange flat welding Ring Loose Sleeve Flange Ring Groove Flange and Flange Cover Large Diameter Flat Flange Large Diameter High Neck Flange Blind Plate Butt Welding Ring Loose Sleeve Flange Rotary Flange Anchor Flange Overlay Welding / Overlay Welding Flange Flange connection is to fix two pipes, pipe fittings or utensils on one flange plate respectively, add flange pads between the two flange plates, and fix them together with bolts to complete the connection. Some pipe fittings and equipment have built-in flanges, which are also flanged connections. Flange connection is the core connection method of pipeline construction. Flange connection is easy to use and can withstand relatively large pressure. In industrial pipelines, flange connections are widely used. In the home, the pipe diameter is small, and it is low pressure, and the flange connection is invisible. If it is in a boiler room or a manufacturing site, there are flanged pipes and appliances everywhere.