Flange, also known as a flange disk or boss, is a component used for connecting shafts to each other, typically for pipe end connections; it is also used on equipment inlets and outlets, such as reducer flanges. A flange connection or flange joint refers to a detachable connection formed by the combination of a flange, gasket, and bolt, serving as a sealing structure. Pipe flanges are flanges used in piping installations, while on equipment, they refer to the equipment's inlet and outlet flanges. Flanges have holes and bolts that secure them tightly together. They are sealed with a gasket. Flanges come in threaded (screwed) connections,焊接 (welded) flanges, and clamp flanges. Flanges are used in pairs; low-pressure pipelines can use threaded flanges, while those above four kilograms of pressure use welded flanges. Two flange disks are joined with a sealing pad and then fastened with bolts. Flange thickness and bolt types vary with pressure ratings. Equipment like pumps and valves, when connected to pipes, have corresponding flange shapes for local connections, also known as flange joints. Any connection piece that uses bolts to connect two flat surfaces and seal them is generally called a "flange," such as in ventilation pipe connections. These components can be referred to as "flange-type parts." However, such connections are only a part of a device, like the connection between a flange and a pump, so it's not appropriate to call the pump a "flange-type part." Smaller items like valves can be called "flange-type parts."
