The European Pipeline Research Group (EPRG) undertakes a wide range of research directed towards the increased integrity and safety of gas pipelines. Topics such as corrosion, fit-for-purpose assessment, and pipeline rehabilitation constitute the major areas of concern for existing pipelines. Whereas areas of concern for new pipelines, in the ever-expanding European gas grid, such as the use of higher strength steels and higher hoop stress factors, and new fluids provide new challenges and opportunities for cost-effective pipeline construction and operation.Collaboration on international research programmes, through industry bodies such as EPRG, is essential to ensure we benefit from leveraged research. Continued participation in EPRG allows National Grid and Cadent Gas to develop a breadth and depth of knowledge that can only be realised through leveraged research programmes, providing maximum cost effectiveness to the customer.
Benefits
The benefits of participating in these European leveraged projects will enable National Grid and Cadent Gas to develop and implement best practice for a fraction of the full cost.
Learnings
Outcomes
Progress 2024-2025
The key projects from 2024-2025 are listed below with relevant findings and project outcomes:
Project 240 – Round Robin Linepipe & Hydrogen
The EPRG Round Robin (RR) project is an industry‑wide interlaboratory study focused on fracture toughness testing of linepipe steels in hydrogen gas. The project addresses gaps in standardisation, test execution, and data post‑processing for rising displacement (J‑R) fracture toughness tests in hydrogen environments, using ASTM E1820 as the base standard with overlays from ANSI/CSA CHMC‑1 and EPRG draft guidelines. A total of 29 laboratories worldwide are formally participating, with Sandia National Laboratories acting as the lead laboratory, and additional non‑RR labs testing the same material independently. A modern L450 TMCP linepipe steel is used to generate consistent, comparable data. The overarching aim is to align industry capability, reduce scatter between laboratories, and feed learnings into future codes, standards, and EPRG guidelines, supporting safe hydrogen pipeline infrastructure development.
Project Outcomes and benefits:
A common test protocol for fracture toughness testing in hydrogen gas has been successfully defined and agreed across a large, diverse set of laboratories.
The RR is structured to capture real‑world scatter arising from differences in instrumentation, crack‑growth monitoring methods (EPD vs compliance), impurity control, and post‑processing choices.
Project 241– Residual Stress (Project Kicked off in 2026)
Project focused on understanding the effect of welding-induced residual stresses on the structural integrity and fracture behaviour of transmission pipelines.
Project 244– Dent Gouge Report
The project consolidates over 30 years of EPRG and industry research to improve the static assessment of pipeline dent‑gouge defects, which are known to cause very low failure pressures and reduced fatigue life. It integrates findings from previous EPRG projects and PRCI ILI performance trials, into a single validated dent gouge assessment framework.
Project Outcomes and benefits:
The new model reflects the underlying failure mechanisms (fracture vs plastic collapse) better than the legacy model.
Stronger alignment with industry standards- uses BS7910 option 1 Failure assessment diagrams and ASME B31.8 dent strain formulations, improving consistency with modern codes.
Enhanced use of ILI data.
ILI‑based failure pressures were on average ~8% lower than laser‑scan‑based predictions; most results fell within ±22%, excluding outliers.
72% of gouge depths within ±20% wall thickness
Including local dent imprints can significantly reduce predicted failure pressure (up to ~44% in extreme cases).
Lessons Learnt
There is a significant volume of work being undertaken by EPRG that is of value to National Gas and Cadent, especially with regards hydrogen and carbon dioxide transmission. Resource should be made available to fully exploit the learnings from projects and to more actively contribute to project definition and delivery. Projects run via EPRG are likely to represent better value for money compared to projects initiated directly by National Gas or Cadent and so should be pursued where appropriate.
Through the projects pursued the following lessons have been learnt for the future projects:
Strategic & Industrial Learnings:
Collaboration is critical to share expertise, reduce duplication and improve cost efficiency
Cross industry knowledge dissemination opportunities.
Structured governance through plenary group and technical committees drives research
Exposure to international experience helps solve current challenges on the network and prepare for future risks.
Technical Learnings:
Pipeline integrity remains a core challenge around areas like corrosion, material performance, ageing assets and fit for purpose assessments.
Design rules and standards for repurposing existing assets for hydrogen transition is a major focus area
