Flange, also known as a flange disk or rim, is a component used for connecting shafts to each other or for joining pipe ends; it is also used on equipment进出口 for connecting two devices, such as a reducer flange. A flange connection or flange joint refers to a removable joint formed by the combination of a flange, gasket, and bolt for sealing purposes. Pipe flanges are flanges used for piping in pipeline installations, while equipment flanges refer to the进出口 flanges on equipment. Flanges have holes and bolts are used to tightly secure them together. Seals are placed between the flanges. Flanges are available in threaded (screwed) connections, welding connections, and clamp connections. Flanges are used in pairs; low-pressure pipelines can use threaded flanges, while those above four kilograms of pressure use welding flanges. Two flange disks are fitted with a sealing gasket and then fastened with bolts. Flanges of different pressures have different thicknesses and require different bolts. Equipment like pumps and valves, when connected to pipelines, have locally shaped flanges that are also called flange connections. Any connection component that uses bolts to connect two flat surfaces and is sealed is generally called a "flange," such as in the case of ventilation pipe connections, these components can be referred to as "flange-like 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-like part." Smaller items like valves can be called "flange-like parts."