Possible Reasons for Selectivity of Corrosive Tube Cracking in Underground Gas-Main Pipelines

The environmental effect of corrosion can cause nucleation and growth of stress-corrosion-caused cracks on the external surfaces of gas-pipeline tubes, thus leading to accidental breakdowns. Peculiar features of corrosive and stress-corrosive flaws along a pipeline route are analyzed in this study and probable reasons for nucleation and propagation of stress-corrosion-caused cracks are discussed. It is forecasted that crack sources can be gradually exhausted with an increase in the operating time of the existing gas-main-pipeline system and this type of damage will decay naturally.