Flange connections involve securing two pipes, fittings, or equipment to separate flange plates first, then inserting a flange gasket between the two plates and tightening them together with bolts to complete the connection. Some fittings and equipment come with a built-in flange plate, which also falls under flange connections. Flange connections are an essential 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 pressure is low, flange connections are not visible. However, in boiler rooms or production sites, flange connections are abundant on pipes and equipment.

Flanged connections can be categorized by type of connection as: flat焊接flanges, socket焊接flanges, weld neck flanges, slip-on flanges, threaded flanges, blind flanges, weld neck loose flange, flat face loose flange, ring groove flange, and blind flange, large diameter flat flanges, large diameter high neck flanges, winged blind flanges, and slip-on weld neck flanges, etc.