PRCI Releases Interim Recommendations for Mitigation of Low-Strain Girth Weld Failures
Early findings from the PRCI project MATH-5-3B, have prompted the release of a technical bulletin entitled Guidance on the Use, Specification, and Anomaly Assessment of Modern Linepipes which provides interim recommendations for enhanced specifications for linepipe purchases and improved welding practices. Webinars were scheduled for 20 and 27 May.
This 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 weld metal strength under-matching, heat-affected zone (HAZ) softening, and 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.
The technical bulletin does not cover all the measures that can be taken to minimise the probability of low-strain failures, nor does it guarantee that such failures will not occur. The completion of the final phases of MATH-5-3B may result in an update to this guidance with additional details 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.