Flange, also known as a flange disc or raised rim. A flange is a component that connects shafts together and is used for pipe-end connections; there are also flanges used on equipment inlets and outlets for connecting two pieces of equipment, such as reducer flanges. Flange connection or flange joint refers to a removable joint consisting of a flange, a gasket, and bolts, used as a combined sealing structure. Pipe flanges refer to the flanges used in piping systems within equipment, while equipment flanges are those on the inlets and outlets of the equipment. Flanges have holes, and bolts secure them tightly together. They are sealed with a gasket. Flanges come in threaded (screwed) connections,焊接 flanges, and clamp flanges. Flanges are used in pairs; low-pressure pipes can use threaded flanges, while flanges for pressures over 4 kg use焊接 flanges. A sealing pad is placed between the two flange discs and then secured with bolts. Flanges of different pressures have varying thicknesses and require different bolts. Pumps and valves, when connected to pipes, have corresponding flange shapes for their local connections, also known as flange joints. Any connection piece that uses bolts to connect two flat surfaces around the circumference and is sealed is generally called a "flange," such as the connections in ventilation pipes, which can be referred to as "flange-like components." 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 component." Smaller items like valves can be called "flange-like components."