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; it is also used at equipment inlets and outlets, such as reducer flanges, for connecting two pieces of equipment. A flange connection or flange joint refers to a removable connection consisting of a flange, a gasket, and bolts, which together form a sealing assembly. Pipe flanges are the flanges used in piping systems, and on equipment, they refer to the equipment's inlet and outlet flanges. Flanges have holes for bolts to secure them tightly together, and they are sealed with a gasket. Flanges are available in threaded (screwed) connections, welding connections, and clamp connections. Flanges are used in pairs; low-pressure piping can use threaded flanges, while those above four kilograms of pressure use welding flanges. Two flange disks are joined with a sealing gasket and then fastened with bolts. Flanges of different pressures have different thicknesses and require different bolts. Pumps and valves, when connected to pipes, have locally shaped flanges to match, also known as flange connections. Any connection piece that uses bolts to connect two flat surfaces and is sealed is generally called a "flange," such as the connections on ventilation pipes. These types of components can be referred to as "flange-type parts." However, such connections are only a 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 part." Smaller items like valves can be called "flange-type parts."