IN-LINE INSPECTION TOOLS FOR CRACK DETECTION IN GAS AND LIQUID PIPELINES

摘要

A new generation of internal inspection device for the detection of cracks in pipelines is described. Since its commercial introduction in October 1994 the crack detection tool described here has successfully inspected over 2,000 km (1,250 mi.) of operating oil and gas pipelines. The runs were followed by verification excavations at specific locations selected from the collected data. Comparison of the findings with corresponding verifications from excavations illustrate the sensitivity and reliability of the inspection method and the ability of the tool to accurately discriminate between different types of defects. The performance has proved the tool to be a reliable internal inspection device for the detection of cracks (SCC, fatigue cracks and crack like defects) in pipelines. As a result, the German TUV (authorized by the German Government to verify the compliance with Regulations covering the operation and inspection of pipelines) has approved the use of this inspection tool as a substitute for in-service hydrostatic pressure testing of pipelines.