Flange, also known as flange disc or flange. A flange is a part that connects between pipes and pipes, and is used for the connection between pipe ends; There are also flanges used on the inlet and outlet of the equipment, which are used for the connection between two equipment, such as the reducer flange. Flange connection or flange joint refers to the detachable connection of flanges, gaskets and bolts connected to each other as a set of combined sealing structures. Pipe flange refers to the flange used for piping in piping installation, and used in equipment refers to the inlet and outlet flange of equipment. There are holes in the flanges, and the bolts make the two flanges close together. The flanges are sealed with gaskets. Flange sub-threaded connection (threaded connection) flange, welded flange and clip flange. The flanges are used in pairs, and the wire flange can be used for low-pressure pipes, and the welded flange is used for pressures above four kilograms. A gasket is added between the two flanges and then bolted. The flange thickness is different for different pressures, and the bolts they use are also different. When the pump and valve are connected to the pipeline, the parts of these equipment and equipment are also made into corresponding flange shapes, also known as flange connections. All the connecting parts that are bolted around the periphery of the two planes and closed at the same time are generally called "flanges", such as the connection of ventilation ducts, this kind of parts can be called "flange parts". However, this connection is only a part of the equipment, such as the connection between the flange and the pump, so it is not good to call the pump "flange parts". Relatively small ones, such as valves, can be called "flange parts". The reducer flange is used for the connection between the motor and the reducer, as well as the connection between the reducer and other equipment.