Flange connections involve fixing two pipes, fittings, or equipment to separate flange discs first, then inserting a flange gasket between the two discs and securing them together with bolts to complete 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 of 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, flange connections are prevalent throughout the pipelines and equipment.

The types of flange connections, categorized by the connection method, include: flat焊接flanges, socket焊接flanges, slip-on焊接flanges, threaded flanges, blind flanges, loose-tightening flanges with socket welding rings, loose-tightening flanges with flat welding rings, ring-groove flanges, and blind flanges, large diameter flat flanges, large diameter high-neck flanges, blind flanges with a V-shaped end, and slip-on flanges with welding rings, etc.