On the analysis of in-tube flaw-detection results characterizing the state of a trunk gas pipeline with corrosion flaws

Abstract

Today, results of in-tube flaw detection (ITFD) are used mainly to solve routine problems of the provision of service reliability of operating gas pipelines (via the removal or selective repair of damaged pipes). However, the task of nondestructive testing consists in not only the detection of flaws but also in the determination of the principal causes of their appearance. This calls for the use of quantitative indexes of flaw parameters for estimating steady tendencies toward the development of damaging, determining the most essential causes of the formation of detected flaws, and predicting possible dynamics of their propagation as the time of operation of a trunk gas pipeline (TGP) system increases. These tasks can be solved based on an analysis of primary results of ITFD by selecting and using steady quantitative indexes of the total damaging using statistical techniques.

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

“…The process of SCCC nucleation and growth practically does not appear in the regions of corrosive-damage development, in particular, over a Density distribution of (a) corrosive and (b) stress-corrosive flaws along the inspected length of gas-pipeline regions[5].…”