Abstract: On the basis of the theoretical foundations of various assessment methods for corroded pipeline, the assessment formulas for every method were deduced according to their basic hypothesis and calculative method for the surface correction factor of through-wall crack. The current criterions were concluded into three basic types of ASME B31G criterion, API 579 criterion and DNV RP F101 criterion. The theoretical and numerical analyses show that the API 579 criterion is more conservative than the B31G criterion. The conservations of three criterions become lower in the order of API 579 criterion, ASME B31G criterion and DNV RP F101 criterion, and the assessment complexity of three criterions is in the order of API 579 criterion, DNV RP F101 criterion and ASME B31G criterion. Because some pipe-section operates mainly under single inner pressure, the ASME B31G criterion or DNV RP F101 criterion should be used to assess the remaining strength in the corroded pipeline to reduce the conservation of assessment and simplify the assessment programs.

Key words: corroded pipeline, remaining strength, corroded fault, assessment criterion, assessment formula

摘要： 分析了管道腐蚀缺陷各种评价方法的理论基础,导出了相应的评价方法的评价公式。将现有的标准归纳为3种基本的准则,即B31G准则、API579准则和DNV RP-F101准则。理论和数值分析表明:B31G准则评价的保守性低于API579准则。在单一荷载下,3种准则的保守性从高到低依次为API579准则、B31G准则、DNV RP-F101准则,评价复杂程度从高到低依次为API579准则、DNV RP-F101准则和B31G准则。鉴于大多数管段主要在单一内压载荷下运行,为了降低评价的保守性,简化评价过程,对于单一荷载和简单缺陷,腐蚀管道的剩余强度仍按B31G准则或DNV RP-F101准则进行评价。

关键词: 腐蚀管道, 剩余强度, 腐蚀缺陷, 评价标准, 评价公式