Large flange in the use of the process will produce different use value, with different types of produce efficacy and use. Large flange material is different, the production and processing process is also different, so in the use and processing of large flange to pay special attention to the method, in accordance with certain procedures and methods to use.

Large flange common overall large flange with flat welding large flange and butt welding large flange. Flat welding large flange rigidity is poor, the scope of application is the pressure p ≤ 4MPa occasions; butt welding large flange also known as high neck large flange, rigid, suitable for higher pressure and temperature occasions. Large flange sealing surface type there are three: flat sealing surface, applicable to the pressure is not high, the media non-toxic occasions; concave and convex sealing surface, applicable to slightly higher pressure occasions; tongue and groove sealing surface, applicable to flammable, explosive, toxic media and higher pressure occasions. Different nature of large flange fittings in different areas with good product performance, adapt to different occasions and space, the efficacy produced will be different.

Large flange gasket is a kind of plastic deformation, and has a certain strength of the material made of the ring. Most of the gaskets are cut down from non-metal plates, or made by professional factories according to the specified size, and the materials are asbestos rubber sheet, asbestos sheet, polyethylene sheet, etc.; there are also metal package gaskets made of thin metal plates (white iron, stainless steel) wrapped with non-metal materials such as asbestos; there is also a winding type gasket made of thin steel belt with asbestos belt.

Large flanges in high-pressure equipment and pipelines are made of lenticular type or other shapes of metal gaskets made of copper, aluminum, 10-gauge steel, stainless steel. The contact width between the high pressure gasket and the sealing surface of the large flange is very narrow (line contact), and the processing finish of the sealing surface and the gasket is high.

Large flange connection is mainly used for the connection of cast iron pipes, rubber-lined pipes, non-ferrous metal pipes and large flange valves, etc. The connection of process equipment and large flanges are also used for large flange connection.

Large flange connection is mainly characterized by easy disassembly, high strength, good sealing performance, installation of large flange requires two large flange to maintain parallel, large flange sealing surface can not be touched, and to clean up. Large flange gaskets used, to be selected according to the design provisions.

Large flange connection is an important connection mode of pipeline construction.

Large flange is divided into threaded connection (wire connection) large flange and welding large flange. Low-pressure small diameter has a silk connection large flange, high pressure and low pressure large diameter are using welded large flange, different pressure of the large flange thickness and connection bolt diameter and number are different, according to the different levels of pressure, large flange gasket also has different materials, from low pressure asbestos gasket, high pressure asbestos gasket to metal gasket are.