Design and Optimization of Elliptical B-shaped Sleeve Configuration for Oil&Gas Pipeline

Abstract Affected by external loads or pipeline corrosion, oil & gas transmission pipelines may encounter safety hazards during service. In terms of defect repair, both domestic and foreign standards currently stipulate that the permanent repair method is B-type sleeve or tube replacement. Compared to the costly tube replacement, B-type sleeves are undoubtedly the preferred choice for economy and safety. However, due to installation size limitations, conventional sleeves are difficult to repair large deformation defects such as wrinkles and buckling in oil and gas pipelines. This study aims at developing, designing, and optimizing a B-type sleeve for welding repair of irregular defects in oil and gas pipelines. By designing irregular B-shaped sleeves with different curve configurations, the stress levels and concentration coefficients of irregular sleeves at different defect heights and sleeve lengths are calculated. The optimal pumpkin shaped and elliptical curve sleeve configurations are selected as the repair solutions for irregular sleeves. Under the existing limitations of machining and detection accuracy, pumpkin shaped irregular sleeves can be prioritized for application in engineering, while elliptical curve sleeves are considered as alternative solutions.