What is the minimum cathodic polarization requirement according to SP0169?

The minimum cathodic polarization requirement according to SP0169 is 100mV. This standard outlines the necessary criteria to ensure effective cathodic protection for buried or immersed metallic structures. Achieving a minimum polarization of 100 mV is critical because it ensures adequate protection against corrosion by sufficiently shifting the electrochemical potential of the metal in a negative direction.

This value is determined based on extensive research and corrosion studies, indicating that polarization levels below this threshold may not effectively prevent corrosion processes from occurring, which can ultimately lead to structural failures. The choice of 100mV provides a balance that considers factors like varying soil resistivity, the presence of coatings, and other environmental conditions that affect corrosion rates.

By adhering to this standard, practitioners can ensure that their cathodic protection systems are robust enough to protect the metal surfaces adequately from electrolytic corrosion over time.