Flange, also known as a flange disk or raised rim. A flange is a component used for connecting shafts to each other and for joining pipe ends; there are also flanges used at equipment inlets and outlets for connecting two pieces of equipment, such as a reducer flange. Flange connection or flange joint refers to a removable connection consisting of a flange, a gasket, and bolts that form a combined sealing structure. Pipe flanges are the flanges used in piping systems within equipment, specifically referring to the inlets and outlets of the equipment. Flanges have holes, and bolts secure them tightly together. They are sealed with a gasket between them. Flanges come in threaded (screwed) connections, welded flanges, and clamp flanges. Flanges are used in pairs; low-pressure pipelines can use threaded flanges, while those over four kilograms of pressure require焊接 flanges. Two flange disks are joined with a sealing pad and then fastened with bolts. Flanges of different pressures have different thicknesses and require different bolts. Pumps and valves, when connected to pipelines, have corresponding flange shapes for local connections, also known as flange connections. Any connection piece that uses bolts to join two flat surfaces and is sealed simultaneously is generally called a "flange," such as the connection of ventilation pipes, which can be referred to as "flange-type components." However, such connections are only part of a single device, like the connection between a flange and a pump, so it's not appropriate to call the pump a "flange-type component." Smaller devices like valves can be referred to as "flange-type components."