Reclamation Information Sharing Environment (RISE)

This research investigated use of ribbon anodes in a ring configuration as a method of cathodic protection (CP) for water tank interiors. Testing was performed using a laboratory model of a storage tank. The effectiveness of the CP system was determined by measuring polarized potentials and evaluating against NACE criteria for protection. This work also studied the performance of a polysiloxane coating system used in conjunction with the CP system. Findings showed polarized potentials around -1100 mVCSE, which is the threshold for what Reclamation considers over-polarization from a CP system. Because of this, for field applications, designers should consider mitigation of over-polarization by using dielectric material on the anode or current/potential control techniques, such as auto-potential controllers. The visual coating inspection performed after 4.5 months in immersion found no signs of typical coating failure modes. Recommendations for future work include continued observation of the ribbon anode CP system and the polysiloxane system with further time in immersion, which will give insight to performance over the system lifetimes.