Ultrasonic crack inspections based on pulse echo 45° shear wave have been in the market for over 20 years. And as any measurement technique there are some constraints that will influence the recorded data resulting in reduced accuracies. Because of this, pipeline operators motivate ILI vendors to innovate and use technology to close the known gaps and improve detection (POD), identification (POI), and sizing (POS) of crack features.
One of the major gaps from pulse-echo technique is the ability to accurately size tilted features, understanding as a tilt when features have a radial misalignment such as hook cracks. The feature geometry will cause the beam to change trajectory, as a result the recorded signal is attenuated resulting in an underestimation of the feature's depth. This raised the question: how can an ILI tool record accurate data that will allow a proper analysis resulting in the detection, identification, and sizing of tilted features?
The answer to the question was a new technology called Eclipse UCx developed in 2019. It included traditional pulse echo and added a secondary measurement technique called pitch & catch. By combining these techniques tilted features can be sized accurately.
Now, 3 years after the release, this paper will summarize the learnings from the technology beyond its original scope, and present cases where the accuracy of the data received has allowed operators to reduce the number of verifications, cluster feature based on their type, or even to avoid hydrotests amongst others. These decisions would have not been possible without the combination of the measurement techniques available.