Objective Amid the global energy transition and the accelerating pursuit of “dual carbon” goals, large-scale storage and transportation of hydrogen—a clean and efficient energy carrier—have become key bottlenecks for industrial development. Repurposing existing natural gas pipelines for hydrogen transport is an effective way to reduce infrastructure costs and shorten construction timelines.

Methods The program “Flow – Making Hydrogen Happen” (“Flow Program”) of Gascade in Germany was selected as the research subject. The overview, key technological breakthroughs, and standard application practices of the Flow Program were systematically reviewed. Critical technical aspects were analyzed in detail, including material adaptability evaluation, compressor and drive system retrofitting, welded joint performance verification, valve sealing optimization, and metering system upgrading. Differences between Chinese and German X70 pipeline systems in materials, equipment, welding, sealing, and metering were compared, and core divergences in standard systems, retrofitting criteria, material compatibility assessment logic, and pressure classification management were identified.

Results The study found that Germany achieved safe and efficient repurposing of large-diameter, high-pressure natural gas pipelines for hydrogen transport through systematic material verification, scientific retrofitting strategies, and comprehensive mature standards. Its technical experience and standard application model proved highly instructive. Despite a substantial pipeline network and resource base for repurposing natural gas pipelines for hydrogen transport, China remains in the early stages of developing long-distance hydrogen pipeline standards, compatibility assessments for high-grade steel pipes, and technical specifications for key equipment retrofitting.

Conclusion Considering China’s national conditions and the strategic plan of “West–East Hydrogen Pipeline”, this study proposes targeted strategies for material R&D, retrofit planning, equipment upgrades, standard development, and international cooperation. The findings aim to provide technical guidance for repurposing natural gas pipelines for hydrogen transport, support the development of national hydrogen storage and transportation infrastructure, and promote the high-quality growth of China’s hydrogen energy industry.