In a galvanic cathodic protection system, what indicates adequate protection against corrosion?

In a galvanic cathodic protection system, a structure to soil potential of at least 0.85 volts indicates adequate protection against corrosion. This specific voltage threshold is established based on research and standards in the field of corrosion science. Adequate cathodic protection is essential for preventing corrosive damage to underground storage tanks and piping systems.

The voltage potential is measured between the structure (like a tank or pipeline) and the surrounding soil. If the potential is too low, it may indicate that corrosion is actively occurring because the protective current is not sufficient to mitigate electrochemical reactions that lead to corrosion. A structure to soil potential of 0.85 volts or higher provides a sufficient driving force for the cathodic protection current needed to protect the metal structure from corrosion.

This standard reflects a balance where sufficient electrochemical potential is established to ensure that the protected metal remains in a more cathodic, and thus less corroded, state. Monitoring and maintaining this level is critical for the longevity and integrity of storage systems.