PR218-173602-R01 Assessment of Fitness-for-Service for Crack-within-Corrosion Anomalies

Continuous crack defects in corroded areas of pipe have been identified as potential cause failures and significant accidents. PRCI was tasked with providing a model to pipeline operators with detailed step-by-step procedures for evaluating the effect of interacting corrosion and crack threats on the integrity of pipelines. There are several existing assessment methodologies for different types of anomaly such as blunt type and crack-like type. The predicted failure pressure PFP results from existing assessment methods were compared and reviewed in this research. Finite Element Analysis (FEA) is a well-documented tool for the accurate assessment of crack-in-corrosion (CIC). Hence, FEA was used in this research to conduct the PFP assessment the results of which were verified with burst tests performed at the Kiefner laboratory as well as data from previous PRCI research: PR-186-113600, Grinding Limits for Repair of SCC on Operating Pipelines (see Ref 18). Additionally, data analytics methodology was used in conjunction with FEA results to develop a relationship between stress intensity and CIC geometry and material properties. The resultant data-analytics derived equation was subsequently verified against burst test results taken from Hosseini’s 2010 publication (see Ref 3 and Ref 4).