The flange connection type usually comes with a double unit, with washers and some bolts and nuts to connect to each other. (The pipe is welded on the flange first, and then the valve and other equipment are installed on the flange.) When connecting these parts, put the gasket between the two flanges, and then tighten the flange screws so that the two are tightly connected together. Flange connection is convenient, flexible and labor-saving. When the pipeline is repaired, the screws on the flange can be removed, and the corresponding pipeline or valve can be removed. Also replace with new pipes and valves.