Detection and identification of pipeline girth weld

This paper presents a girth weld detection and identification method based on the principle of magnetic flux leakage to locate the defects of pipeline. Accurate locating of such defects is essential for repairing them. Usually, inline inspection tool locates defect by using recoded mileage on odometer. However, such recoded mileage deviates significantly from actual mileage due to the way that inline inspection tool moves in rotation and the accumulative error of odometer. With the increase of mileage, the deviation may increase. In order to pinpoint the defects and characteristic points, weld detector is installed on the tool to locate defects precisely by girth weld of the pipeline identified from inline inspection data. Pull test shows that the identification rate of this method exceeds 95.24%.