关键词: 腐蚀管道, 剩余强度, 腐蚀缺陷, 评价标准, 评价公式

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