Strength of Integral Pipe Flanges : No.1 Stress Distribution in Flange and the Criticism of the Conventional Standards

抄録

There are two points to which special attention should be paid in the design of flanges ; the failure of the flange due to high stresses and the leakage of inner fluid through the gasket seat. The formulas for calculating flange stresses given in the conventional Standards are so approximate as to require further investigation. In this report, the stress distributions in a standard integral flange are analyzed by Finite Element Method, and the effects of the design factors (especially fillet radius and hub taper) on the stress concentration at the fillet are clarified. Then, the stress values obtained by Finite Element Method are compared with the values obtained by ASME and JIS Standards, and it is found that the maximum meridional stress is about one and a half times larger than the maximum stress obtained by ASME or JIS Standard.