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16 APRIL 2017 MATERIALS PERFORMANCE NACE INTERNATIONAL: VOL. 56, NO. 4 MATERIAL MATTERS Continued f rom page 15 particular to optimize survey planning. Areas can be designated for regular sur- veying to monitor the protection provided and the anode consumption rate. Other- wise, for the operator relying on routine CP surveys, the accelerated anode con- sumption may not become apparent until later in the life of the vessel—when the anode depletion can be clearly seen. An additional benef it of the model is that a range of scenarios could be simu- lated to predict outcomes over the life of the structure, so possible problems can be mitigated during the initial design pro- cess. In the FPSO case study, the interfer- ence was found to be particularly sensi- tive to resistance between the chain connector and turret—which emphasized the need for robust earthing connections. Predicted potentials on the vessel at the initial, midpoint, and end of design life. Images courtesy of BEASY. We're busy updating our extensive library of NACE Press books so you can benefit from the convenience of an electronic version! Look for this symbol on your favorite title and take advantage of pure portability! Select titles now available! nace.org/store Design variables such as the break- down of a coating and internal resis- tances of the chains, f low lines, and con- nections are based on the design rules. In practice, however, their actual values can be signif icantly different. By updating the model with data from the ICCP system and the CP survey data during the vessel's operation, the model can be calibrated to the actual performance of the coatings and any electrical resistances. In this way, issues of interference and accelerated anode depletion can be predicted, thereby allowing remedial measures to be planned eff iciently. Many of these interference sources can signif icantly degrade the protection provided to marine and offshore assets unless they are considered during the design phase and as part of integrity management. Computer modeling tech- nologies such as this system, however, can provide valuable information to consider. Source: Robert Adey, John Baynham, and Cristina Peratta, BEASY Software and Services, web site: beasy.com. Contact Robert Adey—email: r.adey@beasy.com. References 1 J. Baynham, T. Froome, "Assessing Interfer- ence Between Sacrificial Anodes on Anode Sleds," CORROSION 2013, paper no. 2344 (Houston, TX: NACE International, 2013). 2 J. Baynham, T. Froome, "Interference Be- tween Sacrificial CP Systems in the Marine Environment," CORROSION 2016, paper no. 7797 (Houston, TX: NACE, 2016). 3 R. Adey, C. Peratta, J. Baynham, "How Inter- ference Can Impact the Life of CP Systems. An FPSO Case Study," CORROSION 2016, paper no. 7454 (Houston, TX: NACE, 2016). —Ben Dubose e BOOK