TPC-Corrosion - Corrosion Working Group (NACE)

Jon Brasher

This standard provides requirements to:(1) help utilities identify structures that may be high risk for above-grade corrosion; (2) inspect the selected structures; (3) categorize the condition of structures based on corrosion degradation; (4) prioritize structures requiring additional inspection based on those findings; and (5) help identify next steps as required.

Scope - This standard provides recommendations to: (1) help utilities identify structures that may be at a high risk for below-grade corrosion; (2) excavate and inspect the selected structures; (3) categorize the condition of structures based on corrosion degradation; (4) prioritize structures requiring additional inspection based on those findings; and (5) help identify next steps as required.

This standard provides a procedure that shall be used to (1) assess structures for atmospheric corrosion; (2) assess the level of risk to the structure in terms of corrosion attack and degradation to the existing coating system; (3) make informed decisions based on those findings as to whether coating repair is needed and if so, to what extent; and (4) apply repair coatings to the structure if applicable. This standard applies to the repair of above-grade atmospheric coatings. For the purposes of this standard, the atmospheric area to be coated is generally comprised of that portion of the utility support structure above the transition zone. This standard is limited to the above-grade and atmospheric portions of utility support structures. It does not address below-grade coating repair within and below the transition zone. This standard does not address foundations or guy anchoring systems. This standard does not cover the coating of aluminum, weathering steel, concrete, or any material other than steel. Likewise, it does not cover the coating of non-support structures such as fencing, buildings, transformers, or other miscellaneous components within the transmission, distribution, and substation systems. This standard does not cover new construction, transition zone, below-grade, or water immersion. These areas of concern are addressed specifically in other NACE/IEEE standards. This standard does not address mechanical or structural damage, mechanical or structural repairs, or structural integrity.

This NACE/IEEE joint standard provides requirements to (1) help electric utilities identify structures that may be at a high risk for below-grade corrosion; (2) excavate and inspect the selected structures; (3) categorize the condition of structures based on corrosion degradation; (4) prioritize structures requiring additional inspection based on those findings; and (5) help identify next steps as required. The standard is limited to the inspection and assessment of steel transmission towers, poles, and substation structures, to include galvanized, self-weathering, and painted mild steel structures, as well as other similar structures.