Pitting corrosion is one of the most dangerous forms of localized pipeline corrosion — forming small, deep cavities in the pipe wall that can rapidly penetrate to through-wall thickness.

Pitting corrosion is one of the most dangerous forms of localized pipeline corrosion — forming small, deep cavities in the pipe wall that can rapidly penetrate to through-wall thickness. Unlike uniform corrosion, pitting creates concentrated weak points that are difficult to detect and can cause leaks with minimal overall metal loss.

Pitting corrosion is triggered by localized breakdown of the protective oxide layer or coating, often due to chloride exposure, stagnant conditions, or microbiological activity. Once initiated, the pit interior becomes anodic relative to the surrounding surface, creating a self-sustaining corrosion cell.

Detection methods include high-resolution MFL pigs (for piggable lines), ultrasonic testing, and aboveground inspection. EMPIT’s CMI technology detects localized corrosion patterns — including pitting — from the surface, distinguishing active pits from stable defects. This active/passive classification enables operators to focus remediation on the most critical threats.