Flange, also known as a flange dish or raised boss. A flange is a component used for connecting shafts to each other, typically for joining pipe ends; it's also used on equipment for connections between two devices, such as reducer flanges. A flange joint or connection refers to a detachable connection consisting of a flange, a gasket, and bolts, all interconnected to form a combined sealing structure. Pipe flanges are flanges used for piping in a pipeline system, while on equipment, they refer to the equipment's inlet and outlet flanges. Flanges have holes for bolts, which secure the two flanges together. They are sealed with a gasket. Flanges are available in threaded (screwed) connections,焊接 (welded) flanges, and clamping flanges. Flanges are used in pairs; low-pressure pipelines can use threaded flanges, while those above 4 kg of pressure typically use焊接 flanges. Two flange disks are joined with a sealing pad and then bolted together. Flanges of different pressures have different thicknesses and require different bolts. When pumps and valves are connected to pipelines, the local parts of these equipment items are also made into corresponding flange shapes, 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 connections in 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."