Acoustic emissions and response for detection and monitoring of flow-accelerated corrosion
University of New Brunswick
The viability of using acoustic emission or response of a pipe under fluid load as a means of detecting and monitoring flow-accelerated corrosion (FAC) was assessed. A system that used PZT piezoelectric elements was designed, built and tested using a straight resistance probe for on-line measurement of FAC within a circulating water loop. Both passive and active measurement techniques were employed to correlate changes in the system’s frequency response to the FAC rate calculated using the measured electrical resistance of the probe. Two probes of identical geometry and one with a larger inner diameter were constructed and tested. The system was studied at neutral water chemistry at conditions where the FAC was stifled and where it was maximized. The probe was exposed to flow rates between 1.3-4.0 L/min. Temperature was maintained at 140 °C to maximize FAC. The experimental results provided evidence to support the proof of concept for the active system to detect and monitor FAC. Suggestions for future work to develop a numerical correlation for FAC monitoring building on the present work were also provided.