Corrosion evaluation of glass fiber reinforced plastic (gfrp) Tanks & pressure vessels using acoustic emission technology
Corrosive environments are used like concentrated hydrochloric acid which is known to react with E-glass fibers. Acoustic emission results reveal different corrosion modes of glass fibers in HCl solutions. For the field applications, full scale GFRP equipment was instrumented with a range of AE sensors. The equipment is used for storage or process of corrosive chemicals. When this corrosive content comes in contact with the GFRP wall, via some failure of the corrosion barrier, this could lead to chemical degradation of the composite. To detect such phenomenon, two approaches were adopted: passive monitoring to detect active corrosion (equipment filled in with the service fluid) and AE monitoring during a proof test (according to ASTM E1067 standard). To correlate these AE measurements, the tanks were visually inspected and dissected. The AE results on field were also correlated with AE results in laboratory. The results of this work clearly show the efficiency of AE technology for glass fiber active corrosion detection. On the other hand, they show a good correlation between the proof tests and AE results of corrosion monitoring. The results of this research are a good basis for standardization of the corrosion monitoring of GFRP by Acoustic Emission.
Keywords: corrosive environment ; hydrochloric acid; E-glass fibers ; acoustic emission