• SPECIAL TOPIC: HYDROGEN / RENEWABLE ENERGY •
Improved creep resistance helps sealing components maintain compression forces for longer periods, reducing the risk of leakage in static sealing applications. Additional testing has shown strong resistance to extrusion under extreme pressures, with some cross-linked PEEK materials demonstrating more than double the extrusion resistance of conventional carbon-filled PEEK grades.
Hydrogen molecules are extremely small and need higher sealing pressures relative to other gases.
range and an extremely low ignition energy, meaning that even small leaks can pose safety risks in confined environments. Several mechanisms can contribute to hydrogen leakage in valves. Diffusion through sealing materials is one pathway, particularly when polymers with relatively high permeability are used in high-pressure environments. Mechanical relaxation of seals due to creep is another common cause.
Pressure cycling can also accelerate leakage. Hydrogen infrastructure frequently experiences fluctuating pressures during compression and distribution, placing additional stress on sealing materials and increasing the risk of fatigue-induced failures.
These combined factors mean that materials used in hydrogen valve components must maintain their mechanical properties under conditions that are significantly more demanding than those encountered in conventional gas systems.
Closing the Material Performance Gap
Many conventional sealing materials were developed for hydrocarbon service, where gas molecules are larger, permeation rates are lower, and operating environments are less aggressive in terms of diffusion and embrittlement effects.
Hydrogen environments present a fundamentally different challenge. The combination of very small molecular size, high diffusivity and, in many applications, elevated pressure and temperature, place significantly greater demands on sealing materials.
As a result, materials that perform reliably in hydrocarbon service may struggle to maintain sealing integrity when exposed to hydrogen over extended periods. This has prompted increased interest in advanced polymer materials engineered specifically for these more demanding conditions.
One example is cross-linked polyetheretherketone( PEEK), such as Arlon 3000XT ®, a high-performance thermoplastic developed to enhance durability under extreme industrial conditions. Cross-linking creates a three-dimensional molecular network within the polymer structure, improving mechanical stability and resistance to chemical attack.
These structural modifications can significantly improve material behavior in hydrogen environments. Testing has shown that cross-linked PEEK materials can demonstrate approximately 40 percent lower creep rates under high-temperature shear loading compared with conventional PEEK grades.
Another key benefit is reduced molecular diffusion. Laboratory testing has confirmed extremely low hydrogen diffusion rates in cross-linked PEEK materials, improving long-term containment performance in hydrogen-rich environments. These improvements are particularly valuable for valve seats, seals, and other components that must maintain dimensional stability under sustained load.
Designing Valves for the Hydrogen Economy
Material innovation alone cannot solve every challenge associated with hydrogen valve reliability. Successful valve design also depends on the interaction between materials, component geometry, and operating conditions. Engineers must consider how sealing materials behave under sustained compression, fluctuating pressure cycles, and elevated temperatures. Understanding creep behavior, permeation rates, and long-term mechanical stability is critical when selecting materials for hydrogen service.
Hydrogen-specific testing programs, therefore, play an increasingly significant role. These tests evaluate material performance under realistic operating conditions, providing data that helps valve manufacturers predict long-term behavior and avoid premature failures.
As hydrogen infrastructure expands, the materials used inside valve assemblies will become increasingly important. The ability to maintain sealing integrity under sustained hydrogen exposure will determine not only valve reliability but also the safety and efficiency of hydrogen energy systems. •
20 Valve World Americas | June 2026 | www. valve-world-americas. com