Short Range Pipe Guided Wave Testing Using SH0 Plane Wave Imaging for Improved Quantification Accuracy

Abstract

Detection and criticality assessment of defects appearing in inaccessible locations in pipelines pose a great challenge for many industries. Inspection methods which allow for remote defect detection and accurate characterisation are needed. Guided wave testing (GWT) is capable of screening large lengths of pipes from a single device position, however it provides very limited individual feature characterisation. This paper adapts Plane Wave Imaging (PWI) to pipe GWT to improve defect characterization for inspection in nearby locations such as a few metres from the transducers. PWI performance is evaluated using finite element (FE) and experimental studies, and it is compared to other popular synthetic focusing imaging techniques. The study is concerned with part-circumferential part-depth planar cracks. It is shown that PWI achieves superior resolution compared to the common source method (CSM) and comparable resolution to the total focusing method (TFM). The techniques involving plane wave acquisition (PWI and CSM) are found to substantially outperform methods based on full matrix capture (FMC) in terms of signal-to-noise ratio (SNR). Therefore, it is concluded that PWI which achieves good resolution and high SNR is a more attractive choice for pipe GWT, compared to other considered techniques. Subsequently, a novel PWI transduction setup is proposed, and it is shown to suppresses the transmission of unwanted S0 mode, which further improves SNR of PWI.

Wireless and battery-operatable IoT platform for cost-effective detection of fouling in industrial equipment

“…In the case of pipe walls, UGWs can travel not only along the shortest, direct path between two points but also helically along the pipe wall (Fig. 2) [5][6][7] . The helical paths can be classified by their chirality, i.e.…”

“…Such indicators might be, for example, a decrease in pressure along the equipment. Direct localization of fouling could be beneficial as it gives a more detailed picture of the equipment and further allows the cleaning of the fouled pipe sections without affecting the rest of the system.Ultrasonic guided waves (UGWs) are used to investigate pipelines over long ranges [4][5][6][7] due to their sensitivity to fouling 8,9 . The wave propagation speed depends on the effective thickness of the pipeline wall, and accumulated fouling has the effect of increasing the effective wall thickness.…”

“…Ultrasonic guided waves (UGWs) are used to investigate pipelines over long ranges [4][5][6][7] due to their sensitivity to fouling 8,9 . The wave propagation speed depends on the effective thickness of the pipeline wall, and accumulated fouling has the effect of increasing the effective wall thickness.…”