Cathodic protection requirements and field conditions vary by asset type. Pipelines, facility piping, storage tanks, marine structures, reinforced concrete, and well casings each present different current-distribution, electrolyte, access, and interpretation issues.
Use this section after reviewing the learning guides so you can apply CP concepts to specific structures and environments.
Start with the asset type being evaluated. The correct survey method, reference electrode, criterion, and limitation language often depend on the structure and exposure environment.
Identify the structure being evaluated before applying criteria or selecting a survey method. A pipeline reading, a tank-bottom fixed-cell reading, and a reinforced-concrete potential survey do not represent the same type of evidence.
Soil, water, seawater, concrete pore solution, tank pads, casings, shielding, and facility grounding can all change CP behavior and interpretation.
Criteria and test methods must be matched to the structure type, governing requirement, reference electrode, and survey condition.
Buried pipelines often emphasize longitudinal current distribution and test-station coverage. Tank bottoms depend heavily on under-tank electrolyte conditions and fixed reference cell reliability. Facility piping may be complicated by grounding, bonds, casings, and complex continuity. Marine structures and reinforced concrete introduce different electrolyte and reference-electrode considerations.