Patent ID: 8322757

Claim:
A coupling flange assembly for connecting a pair of upper and lower steel pipes, comprising: an upper flange assembly having a flange plate including a front side and a plurality of stiffening plates, wherein several bolt holes are set up on the flange plate, wherein the stiffening plates are located on the front side of the flange plate and along an axial direction of the upper steel pipe towards a coupling end surface of the upper steel pipe when in the assembled state; and a lower flange assembly having a flange plate having a front side and a plurality of stiffening plates, wherein several bolt holes are set up on the flange plate, wherein the stiffening plates are located on the front side of the flange plate and along an axial direction of the lower steel pipe towards a coupling end surface of the lower steel pipe when in the assembled state; wherein each of the stiffening plates has an extruding part extending beyond the flange plate and extending radially relative to the steel pipes when in the assembled state, wherein equilibrium contact surfaces are set up at front end surfaces of the stiffening plates, wherein in the assembled state, the coupling end surfaces of the steel pipes contact each other and the equilibrium contact surfaces of both the abutting upper and lower flange assemblies contact each other on a one-to-one basis; and wherein the flange plates of the upper flange assembly and the lower flange assembly are not in contact with each other.