Safety assessment for In-service Pressure Bending Pipe Containing Incomplete Penetration Defects

[摘要] Incomplete penetration defect is a common defect in the welded joint of pressure pipes. While the safety classification of pressure pipe containing incomplete penetration defects, according to periodical inspection regulations in present, is more conservative. For reducing the repair of incomplete penetration defect, a scientific and applicable safety assessment method for pressure pipe is needed. In this paper, the stress analysis model of the pipe system was established for the in-service pressure bending pipe containing incomplete penetration defects. The local finite element model was set up to analyze the stress distribution of defect location and the stress linearization. And then, the applicability of two assessment methods, simplified assessment and U factor assessment method, to the assessment of incomplete penetration defects located at pressure bending pipe were analyzed. The results can provide some technical supports for the safety assessment of complex pipelines in the future.

[发布机构] Zhejiang Provincial Special Equipment Inspection and Research Institute, Hangzhou; 310020, China^1

[关键词] Defect location;Periodical inspection;Pressure pipes;Safety assessments;Safety classification;Simplified assessment;Stress linearizations;Technical support