The safety evaluation and life prediction for local wall thinning elbows of high temperature steam pipeline

Local wall thinning defects of high temperature steam pipe would affect the safe operation of pipeline seriously. Considering the internal pressure and bending moment together, the intensity assessment for local wall thinning elbow of steam pipeline has been carried out based on the defect assessment method. According to the relationship between the material creep rupture strength and life at operation temperature, the life assessment for the high temperature elbow was further studied; the residual life and accumulated life fraction of the elbow were finally obtained. The results of the present paper indicated that it is an effective method to perform the safety evaluation and life prediction of the high temperature local wall thinning elbow by use of defect assessment method and high temperature strength theory.