Lap joint flange, is a flange connection method. Its characteristic is that the flange can be loosely connected to the flange of the container or pipe. The flange of the loose flange can be made by flanging, directly turning out or additionally welding the ring.Use flanges, steel rings, etc. to fit the flange on the pipe end, and the flange can move on the pipe end. The steel ring or flange is the sealing surface, and the flange is the function of pressing them tightly. It can be seen that the loose flange does not come into contact with the medium because it is blocked by the steel ring or flange.Lap joint flanges are suitable for situations where frequent disassembly is required in the pipeline system, because the pipes on both sides can be rotated after loosening the bolts, making maintenance and replacement easier.