Monitoring flow-accelerated corrosion in a bent pipe using vibrational methods

Abstract

Damage caused by flow accelerated corrosion (FAC) in piping systems is a major problem that many industries face. Industries must wait until shutdown time in order to inspect the pipes for FAC damage. Because the pipes can only be inspected during certain periods and the inspection time during these periods is limited, a new method that can continuously monitor FAC in piping is needed to address these concerns. An online method that can continuously monitor FAC in piping is introduced. The method uses piezoelectric substrates to continuously measure the resonance frequencies of the bent pipe as its walls thin due to FAC. The resonance frequencies of the pipe were then used to determine the rate of FAC. Previous testing has shown that this method works for a straight pipe. This research project has shown that this method can work for a bent pipe as well. Experiments have been done for a pipe with a 60° and 20° bend angles. The results from these experiments show that there is a strong linear correlation between the change in pipe’s resonance frequencies and the change in average pipe’s wall thickness. These results validate this method as a viable means of monitoring FAC in piping. Further development of this method is needed to improve its capabilities.