Behavior of transporting pipeline sections without and with hydrogen exposure based on full-scale tests

Pipeline transport of hydrogen is one of today’s economic and environmental challenges. In order to find safe and reliable application of both existing gas and build new pipelines, it is essential to carry out tests on full-scale pipeline section, including the potentially more dangerous places than the main pipe, the girth welds. For the investigations, pipeline sections of P355NH steel with girth welds were prepared and exposed to pure hydrogen at twice the maximum allowable operating pressure for 41 days. Subsequently, full-scale burst tests were carried out and specimens were cut and prepared from the typical locations of the failed pipeline sections for mechanical, and macro- and microstructural investigations. The results obtained were evaluated and compared with data from previous full-scale tests on pipeline sections without hydrogen exposure. The results showed differences in the behavior of pipeline sections loaded in different ways, with different characteristics of the materials and the welded joints, both in the cases without hydrogen exposure and in the cases exposed to hydrogen.