| Popis: |
The industry has become increasingly aware of the threat posed by selective seam weld corrosion (SSWC). This has been driven by changes made to gas transmission regulation in 2020 and an increased focus on SSWC as a significant threat in both gas and liquid pipelines. A number of historical publications exist, which provide guidance on how corrosion interacting with the long seam can be addressed. However, there has been very little presented in recent years to encompass current understanding of how corrosion on the long seam, and specifically SSWC, can be managed amid present regulation requirements. Operators have recent experience that can be used to develop an optimized approach that includes technology improvements and a much more informed knowledge of how SSWC differs from coincident corrosion. The aim of this paper is to build on existing guidance and present an optimized approach for managing corrosion interacting with the long seam, with particular attention on differentiating SSWC from coincident corrosion crossing the long seam and defining how both can be assessed to create effective remediation plans. The flow chart considers both types of corrosion and leans on existing guidance and models that can be used to assess anomalies. A key part of the process is to consider susceptibility, material properties and appropriate in-line inspection (ILI) assessments in order to define the most suitable approach based on data and a thorough understanding of the individual pipeline system. Examples will be used to illustrate how the approach can be implemented and on what basis decisions can be made to move through to an optimized remediation plan. |
