Hydrogen, Sampling and Corrosion Insights

2024 In Review: The Debut of "Ask Swagelok."

This past year, we were excited to introduce a new video series called “Ask Swagelok,” where Swagelok experts answer key questions and offer insights into all things fluid systems design. To date, we have published five different conversations with experts each exploring a different topic:

Liquid Sampling

Swagelok Fluid Sampling expert Matt Dixon discusses some of the less widely known aspects of liquid sampling, such as what the role of an outage tube is, how the rate of thermal expansion inside the cylinder could actually rupture the cylinder without proper vapor space compression, how sample cylinders fill, and how vapor space is affected by sampling system design.

Highlights from this conversation:

• Why liquid-filled metal cylinders always need to contain a vapor space to minimize risk of catastrophic cylinder rupture.
• How liquid enters a sample cylinder and how often overlooked factors like return pressure impact the vapor space.
• What is vapor space compression and how can you account for it by understanding the supply pressure, return pressure, and the sampling procedure.
• How downstream components can increase back pressure, the unexpected effect it has on vapor space, and how to maximize vapor space size.
• How sampling procedures affect vapor space and how something as simple as closing both the supply and return valves at the same time can minimize the chance of issues.

Hydrogen System Design

Designing fluid systems for hydrogen is vastly different from designing for oil and gas facilities, and in this conversation, Chuck Hayes, Swagelok’s global technical lead for clean energy, explains why— and how the extremely small size of hydrogen molecules impacts everything from bore sizes to material choices.

Highlights from this conversation:

• How the scale of oil and gas systems is different from hydrogen systems, and why tubing is preferred for hydrogen over the large pipes used in oil and gas.
• How hydrogen’s small size, which allows it to escape systems that oil and gas can’t, makes Swagelok’s tube fittings a better choice than cone and thread fittings for joining components with a well-sealed continuous pore structure.
• How changes in hydrogen density under compression makes it difficult to estimate pressure drop or velocity, and why oversizing is not a viable solution in a hydrogen system.
• Why tried-and-true, cost-reducing methods for sourcing oil gas components suppliers don’t work as well for a hydrogen system, where any leak greater than 1% poses a major safety risk.

Hydrogen Embrittlement

Although hydrogen embrittlement has long been a known problem, for many in the rapidly growing and dynamic field of hydrogen energy, it can be difficult to grasp. In this conversation, Swagelok Senior Scientist for metallurgy Buddy Damm, and Cal Brown, Senior Scientist for new product development, explore what hydrogen embrittlement is, how components can be affected, and what can be done to counter embrittlement issues.

Highlights from this conversation:

• What hydrogen embrittlement is, how and where it starts, and how it lowers ductility and resistance to metal fatigue and fracture in engineering alloys.
• Why hydrogen embrittlement is sometimes a major problem and sometimes no problem at all, and how knowledge of the three major factor— tensile stresses like pressure and static or dynamic loads, availability of atomic hydrogen, and material susceptibility—can help you deal with it.
• How relative reduction in area testing and stress analysis informs proper material selection for components to help mitigate the slow accumulation of damage that can lead to component failure.
• How Finite Element Analysis, and physical product testing such as accelerated impulse testing and cyclic testing all contribute to optimum product design for hydrogen.

Offshore Corrosion

Of all the challenges of an offshore oil and gas environment, corrosion -- both internally and externally influenced -- may be one of the most difficult to combat. Swagelok Senior Scientist for metallurgy Buddy Damm discusses what to look for and what can be done to mitigate corrosion in this conversation.

Highlights from this conversation:

• How electrochemical reactions cause oxidation and reduction reactions in metals, resulting in thinning, loss of pressure containment, pitting, cracking, or crevice corrosion.
• How the two different types of corrosion—externally influenced, by the environment, and internally influenced, by the hydrocarbons being extracted—combine to make corrosion a problem for offshore applications, and how adhering to the NACE MRO 175 or ISO 15156 standards can help.
• How thick components and coatings mitigate uniform corrosion, materials with similar corrosion susceptibility combat galvanic corrosion, a higher chrome steel fights pitting and crevice corrosion, higher nickel content deters stress corrosion cracking, and well-designed tubing runs reduce fretting corrosion and resistance fatigue.

Clean Energy Certifications

With different standards all over the world, it can be challenging for designers to know which ones apply and are important. In this conversation, Chuck Hayes, Swagelok’s Global Hydrogen Expert, discusses the ins and outs of clean energy certifications, what pressure classes are, and what resources are available to help.

Highlights from this conversation:

• What the different standards are around the world for hydrogen and compressed natural gas, what the requirements for different types of systems are for each, and what is changing.
• What the different nominal working pressure classes are (one compressed natural gas, two for hydrogen), what the Joule-Thomson effect is and why it requires higher pressure components, and why fueling stations components have to meet even higher pressure standards.
• Where to find letters of attestation, third-party test reports, and certifications, and how to access the expertise of 50 clean-energy trained field engineers around the world who can help with design issues and with navigating local standards compliance.

COMING SOON: Leak Mitigation

Watch for this conversation, to be published soon, which will explore how leaks can be mitigated to prolong system life and maintain productivity.

All of these and all of our future Ask Swagelok videos can be found at https://www.swagelok.com/en/toolbox/ask-swagelok.

We hope you find these videos useful. They’re only the beginning, though, as we plan to keep bringing you more expert insights through Ask Swagelok. If there are topics you’d like us to explore, please let us know—we’re always happy to share any of our expertise and knowledge that may be helpful to you!