Development of Antibacterial Coating Against Sulfate Reducing Bacteria

With the results of intelligent pigging, so many Microbiologically Induced Corrosion (MIC) cases have been observed especially at around 6 o’clock position of heat shrinkable coating applied at girth weld with typical wrinkled shape failure. Though the reason of coating failure is not clear, two primary things can be presumed. One is improper pretreatment before coating application, the other is low grade of the coating used. Both or each respectively combined with soil subsidence could could exert a role. Once the coatings are detached from pipeline surface, cathodic current cannot penetrate into the channel enough to polarize inside. Where sulfate reducing bacteria are redundant around the soil of girth weld, MIC can develop (or proceed) with substantial rate.

Commercial biocides have been tested on the SRB strain (Desulfovibrio desulfuricans KCTC 5786) and a few species were selected in terms of the biocidal efficacy and endurability. Thermal shock effect simulating application temperature was also tested. With the incorporation of biocides into commercial coating materials (i.e., adhesive of heat shrinkable sheet), biocidal efficacy and coating properties were evaluated.