Flanges are parts that connect pipes to pipes and are connected to pipe ends. Flanges are also used in the inlet and outlet of equipment for connecting between two equipment, such as the flange of reducer. Flange connection or flange joint refers to the detachable connection made by connecting flange, gasket and bolt to each other as a group of sealing structures. Pipeline flange refers to the flange for pipe installation and the inlet and outlet flange for equipment. Flanges are perforated and bolted to tighten the two flanges. Gasket seals between flanges. Flange is divided into threaded connection (threaded connection) flange, welding flange and clamping flange. Flanges are used in pairs, wire flange can be used for low-pressure pipelines, welding flange is used for pressure above 4 kg. Seal between two flange plates and bolt them. Flanges with different pressures have different thicknesses and use different bolts. Pumps and valves, when connected to pipes, parts of these devices are also made of corresponding flange shapes, also known as flange connections. Usually in two planes in the periphery use bolt connection at the same time closed connection parts, generally known as "flange", such as ventilation pipe connection, this kind of parts can be called "flange parts". But this connection is only a part of the equipment, such as flange and pump connection, it is not good to call the pump "flange parts". Smaller, such as valves, can be called "flange parts." Reducer flange for connecting motor to reducer and connecting reducer to other equipment. Flange connection, which is the way to connect two pipes, fittings or materials, is to fix them to a flange plate, which is together with flange pad, which is fastened together with bolts. Some pipe fittings and equipment have their own flange, is also a flange connection. Flange connection is an important way of pipeline construction. Flange connection is easy to use, can withstand greater pressure. Flange connection is widely used in industrial pipelines. In the home, the pipe diameter is small, and is low pressure, can not see the flange connection. If you are in a boiler room or production site, there are flanged pipes and equipment everywhere. According to the connection flange connection types can be divided into: plate flat welding flange, with flat welding neck flange, butt welding neck flange, socket welding flange, threaded flange, flange cover, with neck butt welding ring flange, ring flat welding flange come loose, ring groove surface flange, flange cover, large diameter plate flange, large diameter high blind flange, butt welding neck flange, eight words ring flange, etc.