Impressed Current Cathodic Protection

IMPRESSED CURRENT CATHODIC PROTECTION Scene #1: - In Sacrificial Anode Cathodic Protection systems, galvanic anodes are connected to a metallic structure and supply DC current to it. - The structures that receive current are cathodically protected from corrosion. - The galvanic anodes, on the other hand, corrode as they discharge current. - As the size of the structure grows, more galvanic anodes are required to supply enough current to protect the structure. Scene #2: - In large applications, many galvanic anodes are needed to provide the required current. - In these cases, Sacrificial Anode Cathodic Protection systems are not cost-effective. - Some examples of larger applications are bridges, skyscrapers, large ships, dams and pipelines. Scene #3: - To mitigate corrosion in these systems, we need a source of more DC current. - The Solution? - Impressed Current Cathodic Protection. Scene #4: -In an Impressed Current Cathodic Protection System, - We replace galvanic anodes with non-consumable, inert, impressed current anodes. - We use a rectifier to supply DC current. Scene #5: - The rectifier allows us to supply enough DC current to protect the structure by adjusting the rectifier output voltage. - Too little current, and the structure is vulnerable to the corrosion we want to mitigate. - Too much current, and the structure is vulnerable to overprotection. Scene #6: - Overprotection is not just a matter of wasted power. - It can cause coating separation, structure brittleness, and surface deposits (in marine environments). - It can even cause alkaline conditions which promote the corrosion we’re trying to prevent. - Therefore, not only is proper design important, but also close monitoring of the system. Scene #7: - Reference electrodes are often permanently installed as a part of the Impressed Current Cathodic Protection system. - Reference electrodes provide important feedback about how well the system is performing. - They are used to tune the power settings on the rectifier. - They are used for periodic monitoring throughout the life of the structure. - They help us determine if the system is operating correctly. Scene #8: - Both Sacrificial Anode and Impressed Current Cathodic Protection systems are effective methods of mitigating corrosion. Scene #9: - Sacrificial Anode Cathodic Protection systems are typically used for applications where the current requirements are small. - They are also suited for structures that are buried or placed in soil with low resistivity. - Some of these applications could be small storage tanks, small boats, ballast tanks and initial installations of offshore structures. Scene #10: - Impressed Current Cathodic Protection systems are typically used for applications with large current requirements. - These applications could be buried pipelines, large ships, retrofitting of offshore structures and concrete-rebar structures. - Impressed Current Cathodic Protection systems are also more cost-effective for structures buried in soil. Need Cathodic Protection Expertise or Materials to Protect your Structure? Allied Corrosion Industries, Inc. offers a complete range of Cathodic Protection, Corrosion Control and Pipeline Integrity Solutions. Website: https://www.alliedcorrosion.com/ Toll Free: 1-800-241-0809