Tue, May 25, 2021
Early findings from the PRCI project MATH-5-3B, Guidance on the Use, Specification, and Anomaly Assessment of Modern Linepipes have prompted the release of a Technical Bulletin.
A technical bulletin was developed in response to a significant number of manual girth weld failures in newly constructed pipelines. These failures occurred primarily in X-70 grade SMAW cellulosic girth welds. The primary contributing factors to the failures included 1) weld metal strength undermatching, (2) heat-affected zone (HAZ) softening, and (3) elevated stress/strain in the affected girth welds.
It is believed that the implementation of the interim recommendations would significantly reduce the probability of such failures. In addition, this Technical Bulletin provides high-level guidance for Engineering Evaluation that can be applied to confirm that the intent of the interim recommendations has been met or to document alternative approaches from the interim recommendations. However, the Technical Bulletin does not cover all measures that could be taken to minimize the probability of -low-strain failures, nor would they guarantee that such failures would not occur.
The guidance offered in this Technical Bulletin is based upon results from the PRCI project MATH-5-3B, Guidance on the Use, Specification, and Anomaly Assessment of Modern Linepipes, and the Center for Reliable Energy Systems’ work for individual pipeline operators. The Technical Bulletin benefited from the expertise and contributions of the project team members and a joint industry project in the same subject area. The completion of the final phases of MATH-5-3B may result in an update to this guidance with additional detail and results.
A final report will reinforce the findings in the Technical Bulletin, and will include additional recommendations. It is expected to be published within the next 12 to 18 months with the conclusion of the project.