L51810 Guidelines for the Assessment of Dents on Welds

The Guidelines for the Assessment of Dents on Welds describes a method for evaluating the serviceability of pipeline girth welds affected by otherwise plain, shallow indentations that are free to reround under pressure. The user makes a cumulative fatigue damage assessment, considering the effects of dent size, weld quality, and the severity of the pipeline operating pressure spectrum. An accompanying diskette provides a rainflow cycle-counting algorithm for use in evaluating the operating pressure spectrum, along with other spreadsheet tools to facilitate the analysis. The serviceability is established by an estimate of the pressure-fatigue life of the weld-dent combination. Examples are presented. Field inspection and repair issues are also discussed.