NACE SP21424-2018

This standard practice presents guidelines and procedures for use during risk assessment, mitigation, and monitoring of corrosion on underground, cathodically protected steel piping systems caused by proximity to alternating current (AC) power supply systems.

As shared right-of-way and utility corridor practices become more common, AC influence on adjacent metallic structures has greater significance, and corrosion due to AC influence becomes of greater concern. This standard is not intended to supersede or replace existing corrosion control standards, but rather to complement these standards when the influence of AC-powered systems becomes significant.

The effects of lightning and AC power transmission systems on human safety are not covered by this standard. However, the mitigation measures implemented for safety and system protection, as outlined in NACE SP0177, can also be used for AC corrosion control and are cited whenever feasible.