Limit load analysis of heat induction bending pipe (90 .deg.) with thinning on the extrados

The technology has been applied to non-safety-related systems in Shin-Hanul Unit 1 and 2. However, application to the safety-related systems is not decided yet due to lack of application cases and Code and Standard as well as not confirmed safety performance. For application of this technology, several researches are being performed in Korea. In this paper, as a part of those researches, limit load of pipe bend with thinning on the extrados is compared with the other paper which performed same analysis for normal elbow, and applicability of bending technology is reviewed. As discussed earlier, limit load of pipe bend with thinning is not significantly different with normal elbow. When the thinning increases into longitudinal direction, limit load is reduced but converged to specific value, and when it increases into circumferential direction, maximum value of limit load is smaller than normal elbow but not significantly, whereas minimum value is larger. Thus it can be said that there is no serious problem to apply pipe bending technology to the safety-related piping system instead of elbow, even though thickness of extrados is reduced when it is fabricated