Hydrogen
SEALING SOLUTIONS FOR HYDROGEN INDUSTRY
Reliable Sealing Solutions for a Hydrogen‑Powered Future
As industries accelerate toward cleaner energy, hydrogen has become a cornerstone of sustainable innovation. Yet its unique properties—small
molecular size, high diffusivity, and demanding operating conditions—require sealing solutions engineered with absolute precision. Our gaskets for
hydrogen applications are designed to deliver exceptional tightness, durability, and safety across the entire hydrogen value chain. Whether in production, storage, transport, or fuel cell technologies, we provide sealing performance you can trust to keep your operations efficient, compliant, and future‑ready.
UPSTREAM FEEDSTOCK AND CHEMICAL HANDLING
Gaskets for Chemical Resistance in Alkaline Electrolysis – GYLON® 3510 and GYLON EPIX® 3510
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For alkaline electrolyzers and other chemical-heavy hydrogen processes, GYLON® 3510 and GYLON EPIX® 3510 deliver proven sealing performance and long-term chemical resistance. These materials are ideal for handling aggressive media like potassium hydroxide (KOH) feed in electrolysis. GYLON® 3510 and its EPIX® version are widely used in Europe for this purpose, offering excellent creep resistance, sealability, and chemical compatibility. |
Gaskets for Ultrapure Water and Low-Load Applications – STRESS SAVER® 3522 and GYLON EPIX® 3510
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Engineered for high-purity hydrogen systems and low-load flanges, these gaskets offer reliable sealing with minimal creep and excellent performance with limited bolt load. STRESS SAVER® 3522 features raised ribs to improve sealability with non-metallic or polymer cell components. GYLON EPIX® 3510 adds a versatile option for low-load applications with enhanced compressibility and stress distribution. |
HYDROGEN PRODUCTION
Sealing Solutions for Alkaline Electrolyzers – GYLON® 3510 and GYLON EPIX® 3510
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Alkaline electrolyzers require sealing solutions that resist aggressive chemical environments while maintaining performance under low bolt loads. GYLON® 3510 and GYLON EPIX® 3510 are engineered for long-term chemical exposure to caustic media such as potassium hydroxide (KOH) and sodium hydroxide (NaOH). Their exceptional compression retention and low creep help maintain tight seals and prevent hydrogen leaks, reducing the need for retorquing and minimizing system inefficiencies. |
Compressible Sealing Materials for PEM Electrolyzers – GYLON® 3504 and GYLON EPIX® 3504
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PEM electrolyzers feature thin, delicate cell components that require highly compressible, chemically stable sealing materials. GYLON® 3504 and GYLON EPIX® 3504 provide enhanced compressibility, making them well-suited for stack designs with thin sealing surfaces and tight tolerances. When stack geometries require precise sealing surfaces or profiles, Garlock also offers custom-molded or die-cut gaskets designed for low-stress, high-integrity sealing. |
DOWNSTREAM HYDROGEN PROCESSING
Compression Packing for High-Pressure Hydrogen Valves – 9010-EVSP Low Emission Ring Set
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Designed specifically for high-pressure hydrogen valves, 9010 EVSP provides exceptional sealing capabilities, extended service life, and reduced need for adjustments. This fire-safe, low-emission packing withstands elevated or cryogenic temperatures and continuous exposure to hydrogen gas, ensuring safe and reliable performance in compression, storage, and distribution systems. By reducing wear and minimizing maintenance frequency, 9010 EVSP helps operators maximize uptime, maintain regulatory compliance, and minimizes hydrogen losses through valve stems and packings. |
GYLON® Welded Gaskets & Joint Connections
Hydrogen applications – especially in alkaline electrolyzers, pressurized hydrogen systems, and renewable‑energy powered stacks—place extremely
high demands on sealing technology. Welded GYLON® gaskets have proven to be one of the most reliable solutions because they combine excellent
chemical resistance, dimensional stability, and leak‑tightness even under dynamic and demanding conditions.
Welded gaskets are ideal for large‑sized diameters, as the welding process allows manufacturing gasket dimensions far beyond standard sheet sizes without compromising strength or integrity. This capability is especially valuable in hydrogen applications where oversized or complex geometries are common.
Key Benefits
| » Leak‑Tightness for High‑Pressure Hydrogen Systems » Outstanding Chemical Resistance and Material Stability » Precision Manufacturing for Tight Tolerances » Superior Performance Compared to Segmented Gaskets » Long Service Life and Reduced Maintenance » Robust Performance Under Temperature and Load Cycles » Unlimited Size and Flexible Geometry » Proven Success in Real‑World Hydrogen Installations |
Dimensions larger than sheet sizes can be realized – no size limitations.
Less cost intensive gasket due to better sheet usage and less “scrab”.
If gaskets are segmented and without welds:
- Shipping of large sizes can be done with small packaging units
- Due to segmentation, gasket still can be split and be wrapped around unitswithout dismounting the complete unit. Mounting time can be reduced!
- Different joint connections available
- Less warehouse/storage space needed
GYLON® Welded Gaskets and Joint Connections are manufactured from high‑performance GYLON® sheets, for hydrogen applications specifically GYLON® 3504 (blue) and GYLON® 3510 (white).
Both materials combine excellent chemical resistance with minimized cold flow, ensuring long‑term sealing integrity even in demanding industrial environments.
GYLON® & GYLON EPIX®
GYLON® is a calendered high-performance PTFE sealing material available with various modifications. Depending on the modification, different compressibility and recovery properties are given.
GYLON® and GYLON EPIX® Style 3504 & 3510 have been tested by the German technical Federal Institute for Materials Research and Testing (BAM) for hydrogen applications. The test report “Characterization of polymer materials before and after storage in hydrogen” showed very good test results and ideal properties of our GYLON® materials for sealing hydrogen applications.
GYLON® Style 3504 GYLON® Style 3510
GYLON EPIX® Style 3504 GYLON EPIX® Style 3510
STRESS SAVER® GYLON® 3504
Main Segments
| » Chemical & Petrochemical Industry » Food & Beverage » Pharmaceutical » Metal Industry » Power Generation » New Energies H2 / Hydrogen |
Key Benefits
| » Wide range of application & unloading capabilities (QSmin/L = 3MPa*) » Wide temperature range (-268°C to +260°C) » Stopped cold flow » High tolerated load (QSmax 230 MPa*) » High pressure & vacuum duties » Excellent media resistancy ** » Available with inner-/outer eyelet » Good electrical insulating properties » Unlimited shelf-life » Weather and UV resistant |
* Depending on product and application details
** See Garlock resistance table
Certificates / Declarations
| » FDA » BAM » EC1935/2004 incl. EC10/2011 » TA – Luft incl. Blow-out Proof » DIN EN 13555 characteristics » Phthalate free » Silicone free » ADI free (EMEA 410/01) » USP Class VI <87> <88> » USP <281> <661>* » Hydrocheck (Belgaqua)* |
* Depending on product
STRESS SAVER® GYLON® 3522
Garlock’s patented STRESS SAVER® 3522 technology is constructed of 100% pure and restructured PTFE, offering universal chemical compatibility,
limited leachable contaminants, and easy-to-clean contact surfaces with lowest surface energy which does not support bacterial growth. The STRESS
SAVER® 3522 is engineered and designed to work effectively in higher-stress raised face flanges and lower-stress non-metallic flange designs to simplify the selection process and ensure long-term reliability.
Key Benefits
| » Crush-resistant and ideal for both raised face and flat face flanges » Easy-to-clean surface finish that does not promote bacterial growth » Homogeneous construction to avoid permeation, delamination, or leachable contamination |
Features
| » Temperature: -268 °C to +260 °C » Pressure: up to 83 bar » Compressibility (ASTM F36) 20-25% » 100% pure PTFE (No filler) |
Certificates/Declarations
| » FDA » 3A (Sanitary Standard) » EC1935/2004 incl. EC10/2011 » USP Class VI <88> » USP <31>,<87>,<281>,<661> » Phthalate free (declaration) » Silicone free » ADI free (EMEA 410/01) |
Garlock Style 9010-EVSP
The Garlock Style 9010-EVSP Low Emission Compression Packing Ring Set is purpose built to meet the rigorous demands of environmentally critical
valve applications. Style 9010-EVSP allows valve makers to achieve certification to ISO 15848-1 AH.
Its patented cup-and-cone design ensures a precise, consistent seal that minimizes installation variability and enhances long-term performance.
The low-friction profile not only supports ease of valve operation in automated systems but also reduces energy consumption. The incorporation of
diffusion barriers allows very low emission values to be reached.
Key Benefits
| » Patented cup-and-cone design forprecise, consistent sealing » Low-friction profile for reduced energy consumption » Chemically inert, high-purity materials » Engineered for hydrogen sealing (tight sealing of small molecules) |
Features
| » Temperature: -200 °C to +260 °C * » Pressure: 690 bar » pH 0-14 |
* Consult Garlock for other temperatures.
Applications
| » Quarter turn valves » Rising stem valves |
Certificates/Declarations
| » ISO 15848-1 AH » TA-Luft 2021 » API 589 |
Testing results
The GYLON® & GYLON EPIX® gasket types were stored as follows:
1. Storage of more than one week under 150°C at 100 bar in hydrogen gas
2. Storage of at least six days in liquid hydrogen at cryogenic conditions
3. Then examination with regard to their hardness, tensile strength, elongation at break as well as density
4. Comparison of the determined values after H storage with the previously determined values.
The results of BAM mechanical properties sampling show that our 3rd generation seals are suitable to be used in cryogenic and higher temperature H2 environments without damage.
Testing by BAM with excellent results after ageing in cryogenic (-253°C) and gaseous (+150°C) hydrogen (BAM file number 22048064_1: 01-2023).
⮳ Changes are within the error tolerance of the sensors.
To determine the achievable tightness classes, sampling of the technical tightness after ageing at -196°C in the cryogenic range and in the gaseous range at ageing of up to 200°C was carried out at the company GAIST (a spin-off of Münster University of Applied Sciences) in the set-up for the component test according to VDI2290 (still to be adopted).
The following tables show exemplary the achieved values of the sampling (certificates and test reports for the component test according to the new TA-Luft are available).
Conclusion
The results of BAM‘s mechanical properties sampling show that our modified PTFE GYLON® materials of the 3rd generation are suitable to be used in cryogenic and in higher temperature H2 environments without being damaged.
Corresponding test reports and certificates in accordance with the new TA-Luft are available for all results and tests.
Determination of the tightness classes
Good sealing classes can be achieved not only with seals that have been manufactured from one piece. Excellent sealing classes can also be achieved with segmented seals in the gaseous hydrogen environment. As expected, the residual surface pressures in the cryogenic range of the samples were higher than those in the gaseous range at +200°C. These were all rated as good.
Summary of the results
It could be proven that leakage tests under the medium H2 hydrogen always result in exceeding the required tightness class of 1.0x10E- 02 [mg/ (s*m)] under cryogenic conditions as well as under gaseous conditions.
The achieved “worst” results are with 1.39x10E-05 [mg/(s*m)] in the cryogenic range already 1000 times better than required by the TA-Luft and are also in the gaseous state three decades and thus approx. 1000 times better than the limit value of the TA-Luft.
Results obtained from testing with helium can be used to evaluate the technical tightness of a sealing material made of modified calendered PTFE with regard to compliance with TALuft.
Case Study GYLON® 3510
Green Hydrogen Production & Distribution Equipment
Industry
Green Hydrogen Production & Distribution Equipment
Customer
As a leading industrial player in hydrogen production and distribution
equipment, our customer contributes to the global development
of low-carbon hydrogen as a solution for the energy transition. By
its nature, its business model is based on supporting national and
European customers active in industry, mobility, and energy, in their
efforts to decarbonize their activities.
The customer is a genuine “European native” with centers of
excellence in France, Germany, and Italy since the company was
established. Its industrial and commercial base is strongly European.
Background
Hydrogen is an energy carrier that complements the renewable
energy transition. As an energy carrier with multiple applications,
hydrogen plays a key role in the world energy transition. It can be
turned into clean fuel to charge hydrogen vehicles, injected into gas
networks, used as a raw material for industry, or as an energy storage
solution to give the flexibility needed for smart grid monitoring.
Challenges faced
Our customer wanted to ensure that the seals used were suitable
for their hydrogen applications. They had to be media-resistant and
ensure a long service life. In intensive discussions, they wanted
to be informed about tests and results on the subject of hydrogen
applications.
Operating Conditions
1. Media: Oxygen, Hydrogen, KOH (28%) (Potassium Hydroxide)
2. Temperature: 75°C
3. Pressure: 30 bar (g)
Solution and Benefits
Our customer specified GYLON® 3510 for the pipelines in a
green electrolyzer 16MW plant. With the characteristic properties
of GYLON®, and after successful tests, the customer was convinced
to implement GYLON® 3510. Media resistance, service
life and the typical character properties of GYLON® 3510 (white)
have surpassed all competitor materials many times by far.
Garlock GmbH
Falkenweg 1
41468 Neuss
Germany
+49 2131 349-0
garlockgmbh @ garlock.com
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