Flange connection is the process of fixing two pipes, fittings, or equipment onto a flange plate, adding flange pads between the two flanges, and fastening them together with bolts to complete the connection. Some pipe fittings and equipment already come with flanges, which also belong to flange connections. Flange connection is an important connection method in pipeline construction. The flange connection is easy to use and can withstand high pressure. In industrial pipelines, in households, the diameter of the pipeline is small and it is low-pressure, so flange connections cannot be seen. If there are flanged pipes and equipment everywhere in a boiler room or production site.

According to the connection method, flange connection types can be divided into: plate flat welding flange, neck flat welding flange, neck butt welding flange, socket welding flange, threaded flange, flange cover, neck butt welding ring loose sleeve flange, flat welding ring loose sleeve flange, ring groove surface flange and flange cover, large diameter flat plate flange, large diameter high neck flange, eight shaped blind plate, butt welding ring loose sleeve flange, etc.