Continued Investigation into Insulation Driven Stress Corrosion Cracking – Part 2

Abstract Insulation driven stress corrosion cracking has been a persistent failure mechanism for carbon steel assets operating in Northern Alberta since 2014. This cracking mechanism has been characterized by intergranular cracking in uncoated carbon steel, operating between 70 °C and 190 °C, and exposed to wet mineral wool insulation. Pipelines, piping and pressure vessels operating within this window have all been affected. The Alberta Energy Regulator (AER) has released Bulletin 2021-36 and implemented changes to Directive 077 in response to the risk posed by this failure mechanism. Although incidents appear to be concentrated to Northern Alberta, examples of similar cracking are beginning to emerge in other geographic regions. A group of 5 operating companies formed a joint industry project (JIP) in 2021 to share information and investigate this failure mechanism. This paper provides an update on progress made over the past year, with a focus on the development of a suitable test method to identify susceptibility and investigating the root cause. JIP participants hope that presenting this material will increase industry awareness of this issue and encourage collaboration in cases of cracking observed in other regions under similar circumstances.