Abstract
This study focuses on the design rules for hydrogen pipelines made of carbon steel. The hydrogen-specific design guidelines available to date, namely ASME B31.12, IGEM/TD/1 Supplement 2 and DVGW, are summarised in the first part of this study. The second part focuses on pipeline bends. The stress field of a pipe bend under combined internal pressure and in-plane bending is presented. The stress predictions of rigorous numerical models are compared with the code predictions and shortcomings are highlighted. Subsequently, a realistic application example of a buried hydrogen pipeline containing bends is presented. The differences in design requirements between the two codes for different material selections are shown. Finally, fatigue life predictions are established using the conventional “S-N” approach, as well as linear elastic fracture mechanics, highlighting the importance of considering cyclic loading conditions at early design phases of hydrogen projects.
