西四线变壁厚钢管环焊缝内坡口设计方案

Design Scheme of Inner Groove of Unequal Wall Thickness Steel Pipe Girth Weld in the West-east Natural Gas Transmission IV

我国近些年发生多起油气管道环焊缝失效事故,其中超过半数的失效事故发生于变壁厚钢管环焊缝上。针对变壁厚钢管环焊缝凸显的应力集中、焊接质量较差等问题,通过调研国内外相关行业先进经验和工程案例,提出了变壁厚钢管环焊缝锥孔型内坡口改进方案。以西四线(吐鲁番—中卫段)Φ1422 mm天然气管道工程为依托,基于焊接、无损检测、内检测、应力集中等要求,研究、改进了直管与直管变壁厚对接的环焊缝坡口型式,为提高变壁厚钢管环焊缝的焊接质量、提升管道本质安全提供了技术支持。

In recent years,failure of girth welds in oil and gas pipelines is common,and more than half of the failure accidents occurred in transition weld of unequal wall thickness.In order to solve the problem of stress concentration and poor welding quality in the unequal wall thickness girth weld,through the investigation of advanced experience and engineering cases of related industries at home and abroad,the counterbore-tapered inner groove of unequal wall thickness are proposed.Relying on the west-east natural gas transmission IV(Turpan-Zhongwei),based on welding,nondestructive testing,processing,internal inspection and stress concentration,a counterbore-tapered girth weld for joining straight pipes is designed,which provides technical support for improving the welding quality and the service reliability in oil and gas pipeline.