腐蚀缺陷管道剩余强度评价方法选择及应用

基于可靠性的设计与评价方法是天然气管道评价技术的发展方向,对管道剩余强度评价方法进行适用性分析具有重要意义。介绍了ASME B31G准则、修正的ASME B31G/RSTRENG 0.85Ld法、C-Fer法、DNV-RP-F101规范、美国Battle实验室开发的PCORRC法等腐蚀缺陷管道剩余强度评价方法,并利用收集的管道试验数据对5种方法进行适应性分析。基于Monte Carlo模拟方法,计算得出多个参数的影响规律,并利用实际检测数据对在役腐蚀缺陷集输管道进行可靠性评价和剩余寿命的预测。研究表明:在评价对象一致的情况下,5种方法均具有一定的保守性,但在对中低级钢缺陷管道的剩余强度评价中,使用DNV-RP-F101规范更为准确,其操作方便、可靠性高,具有较高的工程应用价值。(图3,表7,参27)

Selection and application of assessment methods for residual strength of corroded pipelines

Reliability-based design and assessment method is the development direction of natural gas pipeline assessment technology and it is of great importance to analyzing the applicability of assessment methods for residual strength of pipelines.The empirical formulas for residual strength of corroded pipelines,i.e.ASME B31G standard,revised ASME B31G/RSTRENG 0.85Ld method,C-Fer method,DNV-RP-F101 specification,and PCORRC method developed by the US Battle Lab,were introduced,and the adaptability analysis was conducted on these five standards with the collected test data of pipelines.Based on Monte Carlo simulation method,the influence rules of multi-parameters were calculated,and the reliability assessment and residual life prediction of in-service corroded gathering and transportation pipelines were carried out with the measured data.The research shows that these five assessment methods are conservative to some extent for the same assessment objects.DNV-RP-F101 method is more accurate in the residual strength assessment of medium and low grade defective steel pipelines.The method is characterized by convenient operation,high reliability and high engineering application value.