FACTORS INFLUENCING STRESS CORROSION CRACKING OF GAS TRANSMISSION PIPELINES: DETAILED STUDIES FOLLOWING A PIPELINE FAILURE - PART 1: ENVIRONMENTAL CONSIDERATIONS

摘要

Following a failure caused by stress corrosion cracking (SCC) on an NPS 8 pipeline in the NOVA Gas Transmission Limited (NGTL) system a detailed investigation was undertaken to understand the contributing factors resulting in the failure. Studies included site characterization using the NOVAProbe, followed by detailed excavation and sampling. In total 1.1 km of pipe was inspected and replaced. This paper will detail the procedures used to investigate the site and the subsequent analysis and characterization of the samples collected. Factors which appear dominant in determining where SCC occurs will be discussed.