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 to complete the connection. Some fittings and equipment come with flange discs already attached, which also fall 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, you may not see flange connections when the pipe diameter is small and the pressure is low. However, in boiler rooms or production sites, flange connections are ubiquitous on pipelines and equipment.

Flange connections can be categorized by connection type, including flat welding flanges, necked welding flanges, necked butt welding flanges, socket welding flanges, threaded flanges, flange covers, necked butt welding ring-type loose flanges, flat welding ring-type loose flanges, ring groove flanges, and covers, large diameter flat flanges, large diameter high-neck flanges, L-shaped blank flanges, and welding ring-type loose flanges.