Flange, also known as a flanged disk or boss. A flange is a component that connects shafts together and is used for pipe end connections; there are also flanges used at equipment inlets and outlets for connecting two pieces of equipment, such as reducer flanges. Flange connection or flange joint refers to a detachable connection made up of the flange, gasket, and bolts working together as a combined sealing structure. Pipe flanges are flanges used in piping installations; on equipment, they refer to the inlets and outlets of the equipment. Flanges have holes for bolts, which secure the two flanges together. Gaskets are used to seal between flanges. Flanges are categorized into threaded connection (threaded flange), welded flange, and clamped flange. Flanges are always used in pairs; low-pressure piping can use threaded flanges, while pressures over 4 kg require焊接 flanges. A sealing pad is placed between the two flange disks, then secured with bolts. Flanges of different pressures have varying thicknesses and require different bolts. When pumps and valves are connected to pipes, these equipment components are also shaped like corresponding flanges, also known as flange joints. Any connection piece that uses bolts to connect and seal two flat surfaces around the periphery is generally called a "flange," such as the connections on ventilation pipes. These types of components can be referred to as "flange-like parts." However, such connections are only a part of a single piece of equipment, 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 referred to as "flange-like parts."