Millennium Projects
Technical Details
Millennium Project Number: M-2004-002
Project Title: Validation and Enhancement of TWI/Petrochem Guide Wave Ultrasonic Inspection Technology for Pipelines
Project Start Date: 2004
Projected End Date: 2007
Technical Details:
Develop a screening tool to detect external and internal corrosion and coating defects in gas pipes. The Long Range Guided Wave Ultrasonic (LRUT) technique has the ability to inspect inaccessible lengths of pipe and to directly detect metal loss defects. It is particularly useful where traditional Direct Assessment or inspection technologies cannot be used.
The objectives of the proposed project are to advance the functional capabilities of the system, complete the tool's field validation and extend the test range and flaw discrimination capabilities of the LRUT technique in coated pipes. Propagation distances are claimed to be on the order of 50-100 feet, but distances vary based on geometry, coating content, and the presence of pipe appurtenances such as valves, tees, etc. The system is ideal for hard to inspect areas, such as pipes that are in casings at highways, river crossings, railroad crossings, etc. The technology combines longitudinal and torsional waves and propagates them at a low frequency with the gas pipe as the guide. A phased array capability makes it possible for ultrasound to be focused at any selected position both along and around the pipe. This is unique and vastly improves both the detection and flaw discrimination capabilities. The contractor is taking a multi-pronged approach to improve performance specific to gas industry pipe corrosion by working on beam focusing and optimizing on transducer orientation, signal timing and software algorithms. The contractor is performing mathematical modeling to investigate the frequency variation and wave mode on current technology limitations. This project could greatly enhance discrimination capabilities when flaws are found and expand the usage of LRUT.
Also funding this project are the following companies: U S Department of Transportation and TWI and their liquid co-sponsors.