FEM Analysis of Cold Flaring Process of SGP Pipe

This paper describes about finite element method analysis of cold flaring process of low carbon steel SGP pipe. These large diameter pipes such as φ216.3 mm are used for a plant as a flow channel of gas and liquid. The connection of pipes are generally welded at the plant. However, the other connecting method are required from a viewpoint of making the plant environment worse by welding. Therefore, flaring process of large diameter pipes were proposed. This flaring process is one of a method of pipe flange forming. The formed pipes were connected used with loose flange. Flaring process was generally hot process, thus it has some problem such as becoming complex of forming machine and accuracy of dimension. In this study, cold flaring process of SGP pipe was proposed to satisfy these requisitions. FEM analysis of cold flaring process were performed to clarify the optimum forming conditions for the flat length of connecting surface such as corner R. As a result, the optimum die corner R was from R6 to R9.