Standards and codes for hydrogen in pipeline infrastructure: testing, qualification, and integrity assessment

This paper presents a comprehensive review of standards and codes for testing, qualifying, and assessing metallic materials and pipeline infrastructure for hydrogen service, with a view to shed light on the gaps and limitations of current procedures for repurposing EU natural gas infrastructure to hydrogen service. Current standards provide a foundational framework for the qualification of materials in hydrogen-rich environments; however, significant gaps persist in addressing the unique challenges posed by hydrogen-natural gas mixtures. This review explores standards for material testing, qualification methods in codes and standards, and design criteria for hydrogen service, with a critical emphasis on structural integrity assessment. Through a detailed analysis of the different documents, the study has identified limitations in existing testing methods and protocols, including insufficient harmonization, vague testing specifications, and an absence of guidelines for evaluating materials in blended environments. Findings highlight an urgent need for harmonization of procedures to facilitate consistent methodologies across different countries in the EU and beyond, as well as for providing the necessary knowledge in terms of design, testing and assessment methods for the hydrogen-natural gas infrastructure. To address these gaps, this review proposes targeted research areas that can support future updates of standards and codes, contributing to safer, more efficient, and globally aligned approaches to hydrogen blending.