Dubbed H2Pipe, the project aims to develop a new code for the design, requalification, construction, and operation of offshore pipelines to transport hydrogen – be it pure of blended with natural gas.

The independent energy expert says current offshore pipeline codes insufficiently cover the transport of hydrogen or hydrogen blends. DNV’s standard for submarine pipeline systems (DNV-ST-F101) includes hydrogen as a listen transport product, says additional considerations are required to meet the target safety level for an increased use of hydrogen.

It notes a special concern is the potential detrimental influence of hydrogen on resistance to cracking in carbon steels.

To address these challenges, in 2021 DNV started the first phase of H2Pipe, an initial test programme looking into the potential degradation of steep pipe mechanical properties to fill gaps in existing knowledge and to explore various test parameters.

“DNV is committed to the energy transition and plays an active role in supporting its customers removing risks around the implementation of clean energy solutions like hydrogen,” said Prajeev Rasiah, Regional Director, Northern Europe, Energy Systems at DNV.

Rasiah added, “The JIP for offshore pipelines is another contribution in the move to decarbonise the energy system, and to ensure an efficient and safe hydrogen infrastructure.”

With the second phase of the project expected to start this quarter (Q1 2023) and last two years, the phase will consist of a comprehensive testing programme to enhance the understanding of the governing hydrogen embrittlement mechanisms and how hydrogen affects the integrity of the line pipe material.

H2 View understands Phase 2 will also include feasibility level design of offshore hydrogen pipelines and a risk assessment study to look at safety aspects of offshore hydrogen pipelines.

In September (2022), DNV revealed it had landed a three-year contract to demonstrate the safe use and conversation of pipelines to transport 100% hydrogen in the UK.

Read more: DNV to demonstrate safe use and conversion of pipelines to transport 100% hydrogen in UK

DNV hopes the phase will provide a detailed guideline offering specific guidance for use in design and repurposing of offshore pipelines for hydrogen transport.

“The results from the JIP will allow us and our partners to further develop the guideline to a level where it can offer direct and detailed support in the design and requalification of offshore hydrogen pipelines,” Jan Fredrik, Helgaker, Senior Engineer and JIP Lead, Energy Systems at DNV commented.”

Helgaker continued, “With real design limitations, industry players will be able to design – or repurpose – pipeline systems fit for the safe transportation of hydrogen, and to implement adequate mitigation measures if necessary.”