Repurposing Legacy Pipeline Ball Valves for Hydrogen Service – A Practical Engineering Assessment
The UK's transition to hydrogen presents significant opportunities to decarbonise the gas transmission network, but also raises important questions regarding the suitability of existing infrastructure. Whilst considerable attention has focused on pipelines, comparatively little has been published on the hydrogen readiness of large-bore transmission valves, despite their critical role in network safety, integrity and operational reliability.
This presentation explores the UK's first comprehensive end-to-end hydrogen readiness assessment of a 36-inch Class 600 three-piece ball valve removed from the National Transmission System after more than 30 years of service. The project investigated whether legacy valves can be safely refurbished and repurposed for hydrogen service, offering a practical alternative to wholesale asset replacement.
The presentation covers the complete engineering assessment process, including detailed strip-down and inspection, material identification, elastomer characterisation, design modifications, refurbishment, high-pressure gas testing and fugitive emissions testing. It also discusses how current industry guidance, including API 6D Annex M and ASME B31.12, was applied to develop a structured assessment and qualification methodology.
In addition to the technical aspects, the session considers the wider commercial and environmental implications of asset repurposing. Comparative cost and embodied carbon assessments demonstrate the potential benefits of extending the life of existing infrastructure, reducing project costs, shortening delivery times, supporting UK supply chains and lowering the overall carbon footprint of hydrogen conversion programmes.
Delegates will gain practical insights into hydrogen-related degradation mechanisms, sealing technologies, qualification requirements, testing protocols and refurbishment criteria. The presentation provides an evidence-based approach to assessing the suitability of existing valve assets and offers a realistic pathway for supporting the UK's hydrogen transmission ambitions while maximising the value of existing infrastructure.