To make hydrogen more controllable, and reduce container volumes, it is often kept at high pressures (typically 350 to 700 bar) or cryogenic temperatures (sometimes as low as -256⁰C). This makes further demands on the seal materials and affects hydrogen’s behavior toward them. The most suitable materials for a specific application will depend largely on the pressure, the temperature, the form of hydrogen (gas or liquid) and the concentration (ranging from hydrogen residues to 100% hydrogen).
350 to 700 bar
down to -256°C
|no leakage, no permeation, no diffusion
Seals should be capable of safely sealing hydrogen for the lifetime of the vehicle. In most cases it is impractical or impossible to renew hydrogen seals in the field. Although elastomer seals are still widely used (in hydrogen tanks), they are not durable enough to resist hydrogen safely in the long term in such a demanding environment. The need for polymer and metal seals which are specifically suited to use with hydrogen will increasingly be recognized in ISO and other standards. With our deep understanding of material properties and our wide scope of design choices, we at Saint-Gobain are well placed to comply with developing safety and performance standards for hydrogen seals.
We have rigorously tested a broad range of polymers and metals for factors including:
Our material choices can be broadly summarized as follows:
For hydrogen seals we focus on fluoropolymers, which offer greater durability and lifespan than elastomers. In addition, we use thermoplastics for components other than seals. Through comparative studies on different fluoropolymer materials, we have established that TFM-based polymers have certain tribological advantages over PTFE-based compounds in hydrogen environments. In hydrogen gas, their coefficients of friction (CoF) and wear rates are especially low. In liquid hydrogen, CoF is similar for PTFE-based and TFM-based materials, but TFM-based polymers show lower wear rates in some cases. Comparing our fluoropolymers with typical elastomers, we find they are much more resistant to hydrogen permeation at high pressure, relatively unaffected by RGD, and capable of withstanding a wide temperature range.
We have identified and selected steel grades whose tribology results in minimal attraction for hydrogen and avoids embrittlement problems.
A further option has been to enclose metal seals in a polymer jacket. This guards against embrittlement and also reduces metal-to-metal wear and noise.
Our spring energized seals are fitted with a metal spring for extra assurance of maintaining a tight seal, even under high pressure.
We create dynamic seals, static seals and other components for use with hydrogen in four main automotive application categories:
|Hydrogen tanks and regulators
|Hydrogen recirculation blower/pump
|Hydrogen fuel cell components
|H2 and LH2 tanks
|Injection / exhaust manifold
|High pressure seals
Spring energized seals
|Disc cup seals and other low friction seals
High Speed Seals
Disc cup seals
|Injection molded parts
|High Pressure Seals
Flap Seals for Exhaust System
Whatever your needs, we will find – and customize as necessary – the ideal hydrogen sealing solution. Our most relevant product groups are summarized below, along with some of their key advantages. We have dynamic seals for rotational, reciprocating, oscillating, vibrating or other moving assemblies, as well as static seals to use in, for example, face seal applications. With our market-leading products, you can be sure of safe containment, pumping, transport and rapid injection of hydrogen without leakage.
High speed lip seals (stamped / machined)
|Low friction seals (polymer, stamped/machined)
|Thermoplastic components (injection molded)
|Resilient metal seals (stamping/roll-forming)
|Spring energised seals (polymer with metal, assembly of polymer seal with spring)
Saint-Gobain’s world leadership on hydrogen seals owes much to a global technical team, focused on hydrogen issues, which brings together our expert knowledge from automotive and other industries. In local R&D facilities and three international R&D centers, our material science understanding, innovation skills and application engineering capabilities are combined to create new solutions. These activities are supported by our strengths in advanced simulation and data engineering, rapid prototyping, in-house testing, and fast product delivery via a worldwide manufacturing footprint.
Tailored to your needs
Like all our products, our Hydrogen Seals will be custom-designed, configured and manufactured according to the requirements of your individual application and order.
Our engineers will work closely with you at all stages to understand and meet those needs precisely. Discuss your challenges with us, engineer to engineer.
January 26th, 2023