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Pulsed Eddy Current (PEC) has been successfully deployed over the last decades for a variety of corrosionrelated applications, most notably for Corrosion Under Insulation (CUI) inspections, Corrosion Under Fireproofing (CUF) and Flow Accelerated Corrosion (FAC). This technology has proven to be an efficient inspection tool, allowing for the detection of corrosion without having to remove coating or insulating material over typical pipes, tanks and vessels. Despite the success of the technique, one limitation of the conventional PEC systems is that achievable productivity is relatively low, especially on thick walls and when an inspection with high spatial resolution is required. Recently, we developed a Pulsed Eddy Current Array (PECA) solution which greatly increase the productivity of the technique. The system is based on a novel pulsed eddy current probe featuring a linear array topology. The proposed probe design offers 46 cm of coverage in one single pass, improving the productivity of a pulsed eddy current inspection by a factor 4 to 10 compared to non-array solutions. The probe can be used on flat and curved surfaces with a diameter down to 15 cm. This is made possible by the non-rigid mechanical design of the probe, so that its main axis can be wrapped around a pipe or otherwise bent to follow the curvature of the inspected surface. Proper analysis of the array raw data requires an adapted analysis algorithm, whose sizing performance on insulated components is presented in this paper along with examples of defect sizing maps of a typical insulated pipe. After more than a half year on the market, significant field experience has been gathered with this technology making it now possible to show results acquired on real-life components. Some of these will be presented, analyzed and discussed. The sizing and productivity performance of the latest improvements of PEC technique are compared to prior art technology, and benefits are discussed.

Pulsed Eddy Current (PEC) has been successfully deployed over the last decades for a variety of corrosion-related applications, most notably for Corrosion Under Insulation (CUI) inspections, Corrosion Under Fireproofing (CUF) and Flow Accelerated Corrosion (FAC). This technology has proven to be an efficient screening tool, allowing for detection of corrosion without having to remove coating or insulating material over typical pipes, tanks and vessels. However, the use of this technique has been severely limited for components wrapped in galvanized steel weather jacket, which abound in some geographic markets. This paper discusses the challenges of working with galvanized steel as well as some of the solutions that allow quality PEC inspection of such components. We present the most recent improvements in PEC technology, that greatly enhance signal quality and defect sizing accuracy when measuring through ferromagnetic weather jacket materials. Laboratory and field results will be presented and analyzed. We present a clear picture of the possibilities and limitations of the current technology, and key improvements over conventional PEC techniques are discussed.

Pulsed Eddy Current (PEC) has been successfully deployed over the last decades for a variety of corrosion-related applications, most notably for Corrosion Under Insulation (CUI) inspections, Corrosion Under Fireproofing (CUF) and Flow Accelerated Corrosion (FAC). This technology has proven to be an efficient screening tool, allowing for detection of corrosion without having to remove coating or insulating material over typical pipes, tanks and vessels. However, the use of this technique has been severely limited for components wrapped in galvanized steel weather jacket, which abound in some geographic markets. This paper discusses the challenges of working with galvanized steel as well as some of the solutions that allow quality PEC inspection of such components. Eddyfi has developed a number of improvements that greatly enhance signal quality and data accuracy when measuring through all kinds of insulation and weather jacket materials. Laboratory and field results will be presented and analyzed in order to offer a clear picture of the possibilities and limitations of the current technology.

Un grand nombre de techniques non destructives (CND) ont été mises au point et utilisées avec succès au cours des dernières décennies sur divers matériaux, notamment pour la détection de défauts surfaciques tels que : fissures, piqûres, corrosion, etc. Celles-ci sont plus ou moins sophistiquées, mais fournissent toutes des informations précieuses sur l'intégrité des structures inspectées, et présentent des avantages et des limites qui leurs sont propres. Des méthodes établies telles que le ressuage et la magnétoscopie sont efficaces, mais peuvent manquer de praticité dans certaines applications. D'autres, comme les courants de Foucault conventionnels (CF), déploient principalement des sondes mono-élément, impliquant des temps d'inspection importants. Les résultats obtenus grâce à ces techniques sont aussi dépendantes des compétences de l'opérateur, des propriétés des matériaux et de la géométrie des structures inspectées. Les avancées de l'électronique ont permis le développement de techniques d'inspection plus modernes telles que les courants de Foucault multiéléments (CFM), ce qui permet d’augmenter la fiabilité et la répétabilité des inspections de surface par rapport aux méthodes plus traditionnelles. En effet, la possibilité d'adapter les configurations de bobines et les modèles de séquençage permet aux utilisateurs d'optimiser la chaîne d'acquisition à leur application. De plus, en multipliant les éléments actifs et en exploitant les capacités avancées de traitement de données, les solutions CFM permettent d'effectuer des inspections plus rapidement, souvent avec moins de préparation de surface. Ils offrent également des avantages supplémentaires tels que l'imagerie de type cartographie (par exemple, les affichages C-Scan 2D et 3D), une meilleure couverture de surface, une facilité de déploiement et l'archivage des données. Enfin, en plus de la détection des défauts, la technologie CFM peut également parfois fournir un dimensionnement quantitatif. Cet article décrit la méthode par courants de Foucault multiéléments ainsi que ses variations, y compris ses avantages et limites. Le déploiement des CFM sur des structures soumises à des conditions environnementales représentatives, est également discuté. Des applications typiques sont présentées, fournissant des informations précieuses sur l'utilisation de cette technique en remplacement de techniques plus classiques.