Flanges are standard. According to different pressure levels and different specifications of flanges, there are sharp bolt numbers and bolt sizes, and bolt holes also have standard sizes. If the outer diameters are not much changed, the pitch and bore diameters of the bolt holes can be unified, and then the connection can be made. If the specifications are very different and cannot be directly connected, the size of the head can be invoked as a transition. Flange, also called flange or flange. The flange is the connecting part between the pipe and the pipe, used for the connection between the pipe ends; it is also useful for the flange on the inlet and outlet of the equipment, used for the connection between two equipment, such as the reducer flange. The flange connection or flange joint refers to a detachable connection in which flanges, gaskets, and bolts are attached as a set of combined sealing structures. Pipe flange refers to the flange used for piping in the pipeline installation and refers to the inlet and outlet flanges of the equipment when used on the equipment. There are holes in the flanges and bolts make the two flanges tightly connected. The flanges are sealed with gaskets. The flange is structured in threaded connection (threaded connection) flange, welding flange, and clamp flange. Flanges are all used in pairs, wire flanges can be used for low-pressure pipelines and welded flanges for pressure above 4kg. A gasket is added between the two flanges and then tightened with bolts. The thickness of flanges with different pressure is different, and the boats they use are also different. When water pumps and valves are connected with pipelines, parts of this equipment are also made into corresponding flange shapes, also called flange connections. All connecting parts that are connected by bolts on the periphery of two planes and are suspended at the same time are generally called “flanges”, such as the connection of ventilation pipes. This type of part can be called “flange parts”. But this kind of connection is only a part of the equipment, such as the connection between the flange and the water pump. It is not good to call the water pump “flange parts”. Smaller ones, such as valves, can be called “flange parts”.