Author: Simon Slater
Advancing Consensus Engineering Guidance for Hydrogen and Hydrogen Blend Pipelines
The natural gas industry is swiftly adapting to the evolving energy landscape, driven by policymakers advocating for a substantial contribution from alternative fuels like hydrogen. Over the past five years, industry focus and research on hydrogen pipelines has increased significantly. In 2023, ROSEN was awarded a contract from the Emerging Fuels Institute (EFI) to create Consensus Engineering Requirements (CERs) for hydrogen and hydrogen blend pipelines. The goal was to establish industry best practice guidance that could be incorporated into ASME B31.8 as a new chapter for hydrogen to accompany the existing chapters for sour gas and carbon dioxide. Simon Slater, a principal engineer at ROSEN, discusses the approach taken to develop appropriate guidance through collaboration with various stakeholders, highlighting the lessons learned and valuable growth opportunities for both the industry and individuals.
Establishing a plan and assembling a team
The remit was clear: create the content for hydrogen in ASME B31.8. However, the path to achieving this objective was less clear. Hydrogen pipelines are currently addressed in ASME B31.12. This code was created by an ASME committee comprising of members from the industrial gas and piping space and published in 2011. There is a section in ASME B31.12 for pipelines; however, it does not adequately address the need for high-pressure transmission and distribution of hydrogen or hydrogen blend pipelines. Since its inception, considerable work has been performed that needed to be incorporated into the ASME code structure.
Integrating the necessary content in ASME B31.12 with all the available guidance from work completed around the world presented many challenges, both in terms of the volume of technical information and managing stakeholder engagement. A clear plan was developed to systematically review existing literature and create content through working groups of relevant experts, each focusing on specific subjects such as design, welding, and materials.
Consensus is the key
The EFI consists of twenty-one operator members who all have a vested interest in the emerging fuels space and require effective codes and standards to facilitate the development of key infrastructure. The EFI is a research institute, and the team has a wealth of expertise and a broad range of opinions on what good looks like. In addition to EFI members, experts outside of the EFI were also on hand to support, with contributions from three key individuals with leading expertise in hydrogen testing, pipeline design, and integrity management. It goes without saying that two minds (or, in this case, more than 21) are better than one. While ROSEN was contracted to lead the effort, we proactively sought to tap into the team members’ expertise, experience, and energy. We did not expect others to carry the load but recognized the value of collaborating with those willing to help. Working together on such an important issue – code guidance for hydrogen pipelines – was essential for success.
Always ask why… and listen to the answers
Throughout the process, we frequently found ourselves asking “why?”. Some aspects of existing codes did not seem to make sense, prompting us to seek answers from the right experts. At times, we challenged existing guidance only to hear, “That is how we have always done it, and it works.” This can be frustrating, but the response also helps us to reflect. Maybe the current way works because we missed a key consideration, did not understand the background and reasoning, or did not fully appreciate how the content applies to other applications outside of transmission and distribution pipelines.
This was an opportunity for growth – practicing empathy and considering others’ perspectives. The input from original ASME B31.12 committee members was crucial in shaping appropriate code language. That ability to consider the needs of others sits alongside the skill of active listening. I recently finished The Power of Patience by M.J. Ryan, which has great guidance on how active listening helps us become better collaborators in life. With so many voices to be heard and issues to deal with on an aggressive schedule, it would have been tempting to try and force consensus, but sometimes, we had to let it ride and listen to the different points of view carefully to ensure we reached consensus.
Active listening is a skill we all need; it is not enough to sit and semi-listen, waiting to make our own point. We must give the stage to others to collaborate. Besides being a fundamental courtesy, it is also critical when working as a team, whether at work or in our personal lives.
It can be a long road, and the sky is unlikely to fall
Some issues were resolved with relative ease. The stakeholders unanimously agreed that girth welds in high-pressure pipelines in class 3 and class 4 locations require 100% volumetric inspection and that testing should follow state-of-the-art guidance, including fracture testing to ASTM E1820 under representative conditions and at the correct loading rate. Other issues, such as determining the maximum allowable hardness level and the need for testing according to ASTM E1681, were more contentious and took many months of discussion and revisions.
Perhaps the most significant change involved transitioning from the qualification options A and B in ASME B31.12 to a low and high-stress design approach. The latter employs an Engineering Critical Assessment (ECA) to ensure a safe and practical design, allowing the use of higher-strength grades that are already employed in natural gas and sour service pipelines.
Socrates once said, “The wisest man is the man who knows he doesn’t know everything.” Recognizing the use of ASME B31.8 across North America and around the world and acknowledging the efforts completed and progressing elsewhere, we sent the draft document to other stakeholders outside the immediate EFI team. This included members from the Future Fuels Cooperative Research Centre in Australia, the European Pipeline Research Group, API 1104 and API 5L hydrogen task groups, the ASME B31.12 international working group, and many more. After six months of work, we were proud of the draft – only to receive over three hundred comments. Initially disheartening, I soon realized this was not a failure, and the sky was not falling; it was an opportunity to refine and improve the document. The feedback – challenging technical content and suggesting structural or language changes – allowed us to enhance the guidance’s clarity, flow, and usability, which are crucial for industry codes.
Patience: Not my superpower, but a valuable skill
The project presented numerous opportunities to practice patience. As project lead, I often felt like the “chief cat herder,” trying to bring together experts with diverse views on the best approach. It is amazing how much discussion can be had about acceptable hardness levels and how many times we flip-flopped on what the value should be – we landed on 275 HV10. The project tested my patience (as I am sure it did others), but fortunately, the collaboration was so exciting and the technical content so interesting that keeping energy levels high was not a problem. We delivered the remit on time, even if I had to be a little more patient than usual.
Collaboration bridges gaps
It was clear that no single individual holds all the answers, even within a team of experts. Even with a large group of exceptional minds, finding a perfect solution may not be possible. Collaboration plays a key role in advancing the industry and fostering learning. We can still learn from others even when we are experts in certain areas. Everyone can bring something to the table. Our European colleagues shared their advanced experience building hydrogen infrastructure, something we did not have in the US. Through wide-reaching collaboration, we were able to develop consensus guidance on critical issues such as material testing for new and repurposed pipelines and weld procedure qualifications. As I write this, we are still resolving challenges with fatigue crack growth curves and the inclusion of residual stress in fatigue analysis. But with patience and continued collaboration, we will get there.
These collaborations are critical for building networks across operators, service providers, research institutions, and regulators. They open endless opportunities for the industry to work together in the future. As we continue to collaborate, we build a web of contacts that can help solve problems more effectively. In the future, when faced with a challenge, I might be able to reach out to dozens, even hundreds, of experts through these networks.
If you would like to read more and look at the Consensus Engineering Requirements, they are available on the PRCI website for free at PRCI.
ROSEN would like to thank all the collaborators who worked tirelessly on the PRCI project and ASME submission. Without the combined energy of all involved we would never have got this far.