Flange, also known as a flange disc or raised rim. A flange is a component used for connecting shafts to each other, serving as a connection between pipe ends; there are also flanges used at equipment inlets and outlets for connecting two devices, such as a reducer flange. Flange connection or flange joint refers to a detachable connection consisting of a flange, a gasket, and bolts, all connected to form a combined sealing structure. Pipe flanges are flanges used for piping in pipe installations, and when used on equipment, they refer to the equipment's inlet and outlet flanges. Flanges have holes, and bolts secure the two flanges together. They are sealed with a gasket. Flanges come in threaded (screwed) connections,焊接 flanges, and clamp flanges. Flanges are always used in pairs; low-pressure pipelines can use threaded flanges, while those above 4 kg of pressure require焊接 flanges. A sealing pad is placed between the two flange discs, and then bolts are tightened. Flanges of different pressures have different thicknesses and require different bolts. Pumps and valves, when connected to pipes, have parts shaped like corresponding flanges, also known as flange connections. Any connection piece that uses bolts to connect two flat surfaces and seal them 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 device, like the connection between a flange and a pump, so it's not appropriate to call the pump a "flange-type component." Smaller items like valves can be called "flange-type components."