Many different variables need to be considered when a bolted flange is to be assembled. Past research on this topic has focused on nut factors, bolting patterns, gaskets, etc. However, there has been little research on the performance of torque as an assembly method.
The performance of various powered and manual torque wrenches is investigated, including accuracy (achieved bolt load versus target bolt load), repeatability (variation in achieved bolt load), and time to assemble. This study compared performance of seventeen different tools including pneumatic, hydraulic, and manual torque wrenches, across four different flange size/rating combinations utilizing two assembly method (Legacy Star and Modified Legacy Star).
This paper builds on the work described in PVP2017-65800 Determining Accuracy and Repeatability of Torque through Powered Equipment. A larger number of flange assemblies were performed compared to the PVP2017-65800 work, using a greater number of tools and flange configurations.
The results of the tests are provided and the implications of the findings discussed, including consideration of tool selection, assembly pattern selection, personnel competence and training, and bolted flange joint component selection and inspection.
