Advanced acoustic emission for on-stream inspection of petrochemical vessels


To appear in the proceedings of Emerging Technologies in NDT, Held 26-28 May 2003, Thessaloniki, Greece

M.F.Carlos, D.Wang, S.Vahaviolos, A. Anastassopoulos


The “Advanced Acoustic Emission (AE) for on-stream inspection” project is a PetroleumEnvironmental Research Forum (PERF) sponsored initiative. The objective of the project is to develop reliableAE technology for on-stream inspection of pressure equipment in the petroleum refining and chemical indus-tries, instead of internal inspection. To achieve this objective, the project has focused on four key areas of devel-opment, including:


• accurate AE source location algorithms,

• quantitative AE-fracture mechanics correlations for fitness for service assessment,

• reliable AE source discrimination techniques, and

• testing guidelines, procedures and inspector qualification.


The completed work items have been integrated into a high-speed, parallel-processing, cost-effective AE systemand are currently being evaluated in lab and field AE tests. Many unique and exciting capabilities have beenimplemented in the “pre-test” AE test planning functions, and “post-test” automated AE data analysis process.Included in the pre-test planning is the capability to predict the AE response in terms of the source moment tensorusing Green’s functions and integration of the actual sensor response with these predictions. Velocity predictioncalculations are aided by three-dimensional dispersion curves (includes signal amplitude) that take into accountvessel material as well as AE source type, orientation and depth in the material. In addition, Fitness for Service(FFS) analysis is integrated into the AE software to provide API 579 Level II analysis to help prioritize AE indi-cations for follow-up inspection. Analysis and results of the various software functions, will be presented toshow the unique “marriage” of past theoretical models to AE and Fracture mechanics FFS assessment.