Failure Pressure Analysis of Interaction Defect Manifold Straight Pipeline Based on Blasting Test

Summary In view of the lack of scrapping standards for a thick-walled manifold straight pipeline with interacting defects, the failure pressure of the manifold straight pipeline with interaction defects was studied through blasting test and failure pressure simulation analysis. Additionally, the mathematical relationship between failure pressure and defect parameters was established. First, based on the blasting test of the manifold straight pipeline with axial double defects, the failure pressure simulation model was verified, and the failure criterion was optimized. The morphological characteristics and simplification methods of erosion defects were investigated by scanning electron microscopy. Subsequently, the influence of different defect parameters on the failure pressure of the manifold straight pipeline was obtained by analyzing the failure pressure of the manifold straight pipeline under different defect lengths, depths, and axial distances. Furthermore, the critical interaction threshold for axial defects in the pipeline was determined through parametric analysis. Finally, based on the failure pressure simulation analysis results of the manifold straight pipeline, the mathematical relationship between the failure pressure and defect lengths, depths, and axial distances was established by nonlinear fitting. The research results can provide theoretical guidance for nondestructive testing of the manifold straight pipeline with interacting defects and ensure the safe service of the high-pressure manifold straight pipelines. At present, the scrapping standard for assessing high-pressure thick-walled manifold straight pipelines has been written based on the research findings, and the standard has been applied as the basis for safety evaluations of such on-site pipelines.