Flange, also known as flange flange or flange. Flange is the part that connects the pipe and the pipe to each other. It is used for the connection between the pipe ends. It is also useful for the flange on the inlet and outlet of the equipment. It is used for the connection between the two equipment, such as the reducer flange. Flange connection or flange joint refers to the detachable connection of flange, gasket and bolt as a group of combined sealing structure. Pipe flange refers to the flange used for piping in the pipeline installation, and used on the equipment refers to the inlet and outlet flange of the equipment. There are holes in the flange, and the bolts tightly connect the two flanges. The flanges are sealed with gaskets. Flange is divided into threaded connection (screw connection) flange, welding flange and clip flange. Flanges are used in pairs, low-pressure pipes can use wire flanges, welding flanges for pressures above 4 kg. Add a gasket between the two flanges, and then tighten with bolts. Flanges of different pressures have different thicknesses, and they use different bolts. When the pump and valve are connected to the pipeline, some parts of these equipments are also made into corresponding flange shapes, also called flange connection. All the connecting parts that are closed at the same time by using bolts around the two planes are generally called "flanges". For example, the connection of ventilation pipes, this type of parts can be called "flange parts". However, this connection is only a part of the equipment, such as the connection of the flange and the water pump, it is not easy to call the water pump "flange parts". Smaller ones, such as valves, can be called "flange parts". The reducer flange is used to connect the motor to the reducer and the connection between the reducer and other equipment.