Remember a job where we found bad pitting under some insulation, way worse than the logs showed. Ryan_sanchez has a point about check ups, but sometimes the find makes you change the game plan on the spot. We ended up doing a full valve section swap right then, which definitely wasn't the original playbook. It's like the corrosion tells you what to do next, not the other way around. More finds probably means more of those surprise calls in the field.
But come on, how often does it really go that far? Most of the time it's just surface rust you wire brush and coat. Seen plenty of "bad" corrosion that just needed a clean-up, not a whole system rebuild. Makes you wonder if some folks are overreacting to every spot they find.