A pipe has a last line of defence, the coating, which is incredibly resilient and protective for years—but not forever. Once it degrades to the point that the metal pipe is unprotected, conditions are ripe for the corrosion triangle to be activated.
The accepted state of the art in corrosion detection and monitoring uses anything from visual inspections and possibly ultrasound to thermography, radiography, or pulsed eddy current. Sometimes the insulation is physically removed to provide access. The data collected are usually assessed in a spreadsheet and result in reactive, risk-based analyses and maintenance. The costs and risks associated with scaffolding rental, set-up and breakdown, and human safety alone are staggering — and that’s without including any of the remedial costs. And all of this affects only small, localised inspection areas.