天然气长输管道腐蚀缺陷评估与剩余寿命预测

Corrosion Defect Evaluation and Remaining Life Prediction of Long-Distance Natural Gas Pipeline

针对天然气长输管道腐蚀缺陷采用三轴漏磁检测,得到管道内外部金属损失缺陷的相关信息,在不同压力和壁厚上,采用Modified B31G和Kastner评价方法计算了管道的剩余强度,并进行了剩余寿命预测。结果表明:基于Modified B31G评价方法,在评价压力3.9MPa下,14处金属损失的ERF值大于1,需要立即维修;基于Kastner评价方法,在评价压力3.9MPa下,没有金属损失需要立即维修;通过剩余寿命预测发现,在评价压力3.9MPa下,有18处金属损失需要在5年内计划维修。

Triaxial magnetic flux leakage testing is adopted to detect corrosion defects in natural gas transmission pipelines to obtain relevant information of metal loss defects inside and outside the pipelines. The residual strength of the pipelines is calculated with Modified B31 G and Kastner evaluation methods at different pressures and wall thicknesses, and the residual life is predicted. The results show that based on the Modified B31 G evaluation method, the ERF value of 14 metal losses is greater than 1 under the evaluation pressure of 3.9 MPa, requiring immediate maintenance. Based on the Kastner evaluation method, at the evaluation pressure of 3.9 MPa, there is no metal loss requiring immediate maintenance. According to the residual life prediction, 18 metal losses need to be repaired within 5 years under the evaluation pressure of 3.9 MPa.