Abstract
A method which takes into account the effects of external bending moment for the load factor based load calculation of pipe flange connections for the sealing performance design is proposed. Previously authors proposed the simplified load calculation method by using the load factor of the pipe flange connection subjected to internal pressure. The present method is the extension of the previous method to handle the external bending moment loading on it. The flange rigidity apparently increases under the external bending moment loading due to the contribution of the torsional rigidity of the flange ring as Koves pointed out. The apparent increase of flange rigidity proposed by Koves has been incorporated into the equivalent axial force representing the applied bending moment by multiplying the flange rigidity increase factor and it is used to the load factor based load calculation to evaluate the changes in the bolt load and the gasket load of the pipe flange connection subjected to the external bending moment. By using the factored equivalent axial force, the equations of the load factor based load calculation can be easily extended to handle the external bending moment.
