Pipetronix has developed a new generation of internal inspection device for the detection of cracks in pipelines. Since its commercial introduction in October 1994 the tool, UltraScan CD (Crack Detection), has successfully inspected nearly 1,000 km 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 UltraScan CD to be a reliable internal inspection device for the detection of cracks (SCC, fatigue and other crack like defects) on pipelines. As a result, the German TÜV (authorized by the German Government to verify the compliance with Regulations covering the operation and inspection of pipelines) has approved the use of UltraScan CD as a substitute for hydrostatic pressure testing of pipelines.