Flange, also called flange flange or flange. Flange is a part that connects pipes to each other and is used for connection between pipe ends; it is also useful for flanges on the inlet and outlet of equipment for connection between two equipment, such as reducer flanges. Flange connection or flange joint refers to a detachable connection in which flanges, gaskets and bolts are connected to each other 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.