Abstract: A coupling flange assembly for connecting steel pipes including coupling flanges having stiffening plates located on the front side of the flange plate along axial directions of the steel pipes towards a coupling surface of the steel pipe to be connected. Equilibrium contact surfaces are set up on front end surfaces of the stiffening plates. Two abutting coupling flange assemblies may be used to connect two steel pipes, and when the two steel pipes are connected, the equilibrium contact surfaces of each stiffening plate of the coupling flange assemblies will be in contact with each other on a one-to-one basis.

Abstract: A flange assembly, a coupling flange, and its assembling method thereof are disclosed. Stiffening plates (2) are located on the front side of the flange plate (1). Equilibrium contact surfaces (211) are set up on the front end surfaces of stiffening plates. The pressure stress bending moment created by the equilibrium contact surfaces offsets the pulling stress on the steel pipe wall and reduces the hoop stress of the steel pipe. This provides reliable bonding strength and ensures that the tensile rigidity remains unchanged under circulating dynamic load. This coupling flange is especially suitable for the connection of large-scale steel pipes such as the cylindrical pylons of large-scale wind power generators. The coupling flange can save steel consumption, reduce machining difficulty, and thus greatly reduce the manufacturing and assembling costs.