Safety criteria for the operation of gaseous hydrogen pipelines

This report discusses safety criteria for the transportation of gaseous hydrogen by pipeline. Major emphasis is placed on transmission pipelines, but distribution piping is also considered. The report concludes that under certain conditions gaseous hydrogen could pose public safety hazards that are not adequately addressed by current safety code regulations. Preliminary criteria for the design of new gaseous hydrogen transmission lines, for converting existing transmission lines to gaseous hydrogen service, for enhanced operating procedures and maintenance practices for mainline transmission systems, and for introducing hydrogen into existing or new distribution systems are recommended.