scope:

This standard provides requirements 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 NACE/IEEE joint standard is limited to the inspection and assessment of weathering steel transmission towers, poles, substation structures, and other similar structures.

It does not address the specific inspection of concrete foundations, above-grade attachment points, or guy anchors. In addition, this standard does not provide procedures regarding repair and/or replacement of these same types of structures.

This standard addresses general and localized corrosion.

This standard does not provide specific pass/fail criteria. Pass/fail criteria are often determined by structural strength considerations, which are beyond the scope of this corrosion-related standard. Users of this standard are encouraged to develop their own specific set of pass/fail criteria based upon their particular design requirements.

NOTE: Additional information on below-grade inspections is available in NACE SP0415/IEEE Std 1895.¹

For the purposes of this standard, the area of inspection is comprised of the transition zone and below-grade portion of the structure. The inspection area and depth of excavation is determined by the utility as appropriate to identify the extent of corrosion. This standard should not be used to address structures in continuous immersion environments.

The definitions of many of the corrosion-related terms used in this standard can be found in NACE/ASTM⁽¹⁾ G193.²

⁽¹⁾ ASTM International (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959.

⁽²⁾ Notes in text, tables, and figures are given for information only and do not contain requirements needed to implement the standard.