Flange connections involve securing two pipes, fittings, or equipment to separate flange discs first, then inserting a flange gasket between the two discs and fastening them together with bolts, thus completing the connection. Some fittings and equipment come with a flange disc already attached, which also falls under flange connections. Flange connections are an important method in pipeline construction. They are convenient to use and can withstand high pressure. In industrial pipelines and residential settings, where pipe diameters are small and the pressure is low, flange connections are not visible. However, in boiler rooms or production sites, you'll find pipes and equipment connected with flanges everywhere.

According to the connection method, flange types can be classified as: flat welding flanges, socket welding flanges, blind flanges, threaded flanges, cover flanges, loose sleeve flanges with socket welding rings, loose sleeve flanges with flat welding rings, ring groove flanges, and large diameter flat flanges, large diameter long-neck flanges, blind flanges with notches, and loose sleeve flanges with welding rings, etc.