公用热力管道缺陷成因分析及安全评定

Cause Analysis and Safety Assessment for Defect of Common Thermal Pipelin

介绍了某热电厂公用热力管道全面检验中发现的裂纹和未焊透两类缺陷。通过受力分析计算出管道在运行状态下的应力分布状况,详细分析了螺旋缝埋弧焊钢管在制造过程中产生裂纹的各种因素,指出应该重视焊接钢管的焊接质量检测。利用GB/T19624—2004《在用含缺陷压力容器安全评定》中给出的压力管道直管段体积缺陷安全评定方法,对环焊缝上适用范围内的未焊透缺陷进行安全评定,结果表明,在正常使用工况下该缺陷未发生扩展时是安全的。

This paper introduces the crack and non-penetrating weld defects founded in overall inspection for common thermal pipelines in a thermal power plant.By force analysis,stress distribution state under running of pipelines is calculated.The various causes of crack emerged from manufacturing process for spiral and submerge-arc welding pipelines are analyzed in detail,finding out that the quality inspection of weld should be valued.Base on methods about volume defects in straight pressure pipelines in GB/T19624—2004 ＂Safety Assessment for In-service Pressure Vessels Containing Defects＂,the safety assessment of non-penetrating weld defect in circumferential weld is conducted and the result has shown that it will be safe in the regular service state if the defect does＇t extend.