Evaluation of rapid gas decompression (RGD) resistance of sealing materials for hydrogen-doped pipeline valves

Abstract With the rapid development of hydrogen-doped natural gas pipelines, the evaluation of the applicability of hydrogen to natural gas pipeline systems is bound to gradually involve all aspects of natural gas pipelines. Targeted at the non-metallic sealing materials for valves of hydrogen-doped natural gas pipelines, this paper, according to the ISO 23936-2 standard, carried out the rapid gas decompression (RGD) tests of hydrogenated nitrile butadiene rubber (HNBR), fluorine rubber 246 (FKM246) and fluorine rubber 26 (FKM26), and the damage level of cracking failure for the rubber materials in the course of rapid release of gaseous medium was obtained (DL). The mechanical properties and volumetric dissolution rate of the three rubber materials were tested before and after the high-pressure gas mixture treatment, which explains the reason for the cracking failure of the rubber materials during the RGD test. The study obtained the influence law of high-pressure gas mixture with different hydrogen volume fractions on the RGD resistance of HNBR, FKM246, and FKM26, and selected the material with the optimal RGD resistance as FKM26, which can be used as a reference for the selection of sealing materials for the valves of hydrogen-doped natural gas pipelines in engineering.