Assessment of Local Defects on the Inner Surface of Gas Pipelines Transporting CO2-Containing Products

Visual inspection control of pitting defects on the manifold lugs cut out of the gas collection header was performed. This has made it possible to compare and determine the measurement accuracy of previously performed in-line inspections of gas pipelines operated in the presence of the corrosive CO 2 in the transported gas. It is determined that the presence of ferromagnetic products of corrosion in local defects negatively affects the measurement of the pipe wall thickness—the local defect depth is 20–30% lower than the real value. After removing corrosion products, it was found that many defects are clusters of corrosion pits combined with each other.