From 2009–2013, 13 pipeline segments with an aggregated length of more than 1,300km were inspected with newer versions of EMAT tools for SCC and crack-like defects, and validated with more than 200 excavations. The EMAT tool performance is evaluated in terms of detection, identification, false calls, and sizing. The evaluation showed significant improvement in tool performance compared to previous years where older generations of tools were used. The performance was validated with confirmatory hydrotests. The reliability of using EMAT tools as the alternative to hydrotesting over a range of steel grades and vintage, coating types were assessed incorporating performance parameters like detection, identification, and sizing tolerance, with assessment methodologies. Based on the available historic data of hydrotesting, the reliability of EMAT ILI was compared to that of hydrotesting.
In this paper, the approach used for the evaluation of EMAT tool performance is presented first. The results and findings are then summarized. Hydrotest and EMAT reliability methodologies and results are presented next. EMAT application to gas pipeline SCC integrity management as an alternative to hydrotesting is discussed.