Custom Hydrogen Fuel-Cell & Cryogenic Sealing
H-O Products die-cuts and converts EPDM, fluoroelastomer (FKM), and silicone stack gaskets, PEN / polyimide subgasket and edge-frame films, expanded-PTFE (ePTFE) and PTFE electrolyzer and cryogenic gaskets, and cellular-glass and ArmaGel® insulation into the seal-and-insulation stack inside PEM fuel-cell stacks, PEM and alkaline electrolyzers, balance-of-plant enclosures, and vacuum-jacketed liquid-hydrogen (LH2) equipment, built to your drawing.
Built for: PEM fuel-cell bipolar-plate stack seals and MEA subgaskets, PEM and alkaline (AEL/AEM) electrolyzer stack gaskets, balance-of-plant enclosure sealing, EMI, and thermal interfaces, and cryogenic / LH2 flange gaskets, valve-seat seals, and pipe insulation, with material compatibility per the vendor TDS and system standards (IEC 62282, CSA/ANSI FC 1, ISO 22734-1) cited by designation.
To seal a hydrogen or cryogenic assembly, choose the material from the chemical environment and the temperature window, then validate hydrogen compatibility per the vendor TDS. For a PEM fuel-cell stack seal, specify EPDM (acid-resistant, good water and gas sealing) or FKM/fluoroelastomer where its temperature and chemistry fit and lower hydrogen permeation is wanted. The remaining zones and duties are mapped in the When-to-spec list on this page. Values are per the TDS on file; see the material reference below for ordering details.
By designation (the listing belongs to the tested stack or system): IEC 62282 (fuel cell technologies, module and stationary-system safety) · CSA/ANSI FC 1 (stationary fuel cell power systems) · ISO 22734-1 (hydrogen generators using water electrolysis) · ISO 14687 (hydrogen fuel quality) · ISO 19880-1 (gaseous hydrogen fuelling stations) · NFPA 2 (hydrogen technologies code) · CGA H-3 / H-5 (cryogenic and bulk hydrogen) · CSA/ANSI CHMC 2 (polymer compatibility in compressed hydrogen) · ISO 23936-2 (elastomer rapid gas decompression).
Material-level, per the maker TDS: ASTM D2240 (durometer) · ASTM D412 (tension) · ASTM D395 (compression set) · ASTM D471 (fluid resistance) · ASTM F36 (gasket compressibility) · ASTM D2137 (low-temperature brittleness) · ASTM C552 (cellular glass) · ASTM C177 (thermal transmission) · ASTM E84 (surface burning).
- PEM stack gasket: EPDM / FKM
- MEA subgasket / edge frame: polyimide / PEN film
- PEM electrolyzer stack: FKM + PTFE
- Alkaline (KOH) electrolyzer: EPDM / expanded PTFE
- Incidental fuel / oil contact: fluorosilicone sponge
- BOP enclosure seal + vent: silicone foam + ePTFE vent membrane
- Cryogenic / LH2 flange: ePTFE / virgin PTFE
- Cryogenic pipe insulation: cellular glass + ArmaGel® DT
This guide is for hydrogen fuel-cell and electrolyzer stack engineers, balance-of-plant (BOP) integrators, and cryogenic / liquid-hydrogen equipment designers and procurement teams specifying stack gaskets, membrane electrode assembly (MEA) subgaskets and edge frames, electrolyzer gaskets, enclosure seals, and cryogenic flange, valve-seat, and pipe-insulation parts, where the seal or insulation has to survive a specific chemical environment and temperature window and its hydrogen compatibility is validated per the vendor technical data sheet (TDS).
Where are you in the spec process?
This page serves engineers who already know the seal or insulation they want and engineers still working the spec from the environment and temperature. Pick the path that matches where you are; you don't have to read the rest.
Send a drawing, get a quote
An EPDM or FKM stack gasket, a PEN / polyimide subgasket, an expanded-PTFE electrolyzer or cryogenic flange gasket, a cellular-glass or ArmaGel® insulation die-cut, or a complete kitted stack seal set on your drawing.
Skip to the quote form →Build the stack requirement by requirement
Six selection factors (chemical environment, temperature window, hydrogen permeation per TDS, seal geometry, BOP integration, cryogenic insulation), a requirement-driven material-stack checklist, and eight material families with TDS-cited grades and by-designation standards language.
Start with selection factors →
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1Send drawingUpload a DXF, STEP, or PDF, or describe the stack, the bipolar-plate seal or MEA frame, the electrolyzer gasket, or the cryogenic flange and insulation. A sample part works too.
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2Material reviewEngineering reviews the chemical environment (humidified hydrogen and air, acidic PEM membrane, hot caustic KOH, coolant, or LH2), the temperature window, and any hydrogen-permeation or rapid-gas-decompression requirement against the vendor TDS, and frames the standards language correctly: material properties and classes by TDS, system standards (IEC 62282, CSA/ANSI FC 1, ISO 22734-1) by designation, listing with the tested stack or system.
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3PrototypeSamples typically ship in 3–5 business days for common configurations on materials we keep on hand. Made-to-order; MOQ varies by material and part.
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4ProductionStandard production runs ship about 2 weeks after drawing approval, including laminated subgasket / edge-frame and kitted stack-seal-set configurations. Expedited service available. Ongoing parts run with material traceability and lot-code TDS records.
Chemical environment & temperature → permeation per TDS → material selection → converted seal or insulation → production supply.
- 1Environment & temperatureName the media (humidified H2 / air, acidic PEM, KOH, coolant, or LH2) and the temperature window.
- 2Permeation & RGD per TDSState any hydrogen-permeation or rapid-gas-decompression requirement to validate per the vendor TDS.
- 3Select material familyEPDM, FKM, silicone, PEN / polyimide film, expanded PTFE, PTFE, cellular glass, or ArmaGel®, matched to the duty.
- 4Add adhesive / liner / framePSA backing, kiss-cut-on-liner, or a laminated subgasket / edge-frame from the drawing.
- 5Die-cut to drawingStack gasket, MEA subgasket, electrolyzer gasket, flange gasket, or insulation to your geometry and tolerance.
- 6Quote prototype or productionSamples, first article, and production supply with lot-code TDS records.
Which hydrogen system are you building?
Application Zones
Six sealing and insulation problems define the hydrogen chain: the PEM fuel-cell stack, where a gasket holds humidified hydrogen and air apart cell by cell; the membrane electrode assembly (MEA) subgasket, the thin film frame that protects the membrane edge and sets the sealing plane; the PEM and alkaline electrolyzer stack, where the seal faces hot caustic or acidic, oxygen-rich duty; the balance-of-plant enclosure around the stack, an environmental, EMI, and thermal problem; the cryogenic / liquid-hydrogen flange and valve seal, where elastomers are below their floor and a PTFE-family fluoropolymer takes over; and the cryogenic pipe and vessel insulation that keeps heat in-leak and boil-off down.
Click a tab to see the joint, the controlling properties, and the families H-O converts for it.
PEM fuel-cell stack: the bipolar-plate seal
A proton-exchange-membrane (PEM) fuel-cell stack is a compressed column of cells, and the gasket between each bipolar plate has one job: hold the humidified hydrogen on the anode and the air or oxygen on the cathode apart, and keep the coolant where it belongs, while the stack breathes through every start and stop.
The seal environment is acidic (a dilute-sulfuric-acid-like membrane, pH about 4–6) with continuous humidified gas, and the temperature window runs from a cold-start floor near −30 °C to about 90 °C for low-temperature PEM, or 120–180 °C for high-temperature PEM.
The material split follows the chemistry: EPDM is acid-resistant and seals water and gas well, and it stays stable after long immersion at 80 °C; FKM/fluoroelastomer suits designs where its temperature and chemistry fit and lower hydrogen permeation is wanted; and silicone (VMQ) is kept off the wet acidic membrane face, where it de-crosslinks by acid hydrolysis.
One sentence governs the paperwork: IEC 62282 and CSA/ANSI FC 1 evaluate the stack or system, the listing belongs to the tested assembly, and hydrogen permeation is validated per the vendor TDS, not claimed as "hydrogen-safe."
MEA subgasket & edge frame: the thin film that protects the membrane
Inside the stack gasket sits a quieter, thinner part: the subgasket, or edge frame, a polymer film and laminated around the membrane electrode assembly (MEA). It protects the fragile membrane edge from the compression and the reactant-gas crossover pressure, sets the plane the stack gasket seals against, and keeps the electrodes from shorting at the perimeter.
The film is thin, typically about 12–125 µm (often 25–75 µm), and it is chosen for heat and durability: polyethylene naphthalate (PEN) and polyester (PET) are the common frame films, and polyimide (Kapton® / Apical) serves where higher temperature endurance or a dielectric class is wanted.
H-O and laminates the frame to the MEA footprint, holding the window and the outer edge to the drawing so the sealing plane is flat and the membrane edge is covered. The film gauge and the frame geometry come off the cell design; the converter's job is a clean, accurate, laminated edge.
PEM & alkaline electrolyzer stacks: hot caustic and oxygen-rich duty
An electrolyzer runs the fuel cell in reverse, and the gasket duty is harsher. In a PEM water electrolyzer the seal sees a dilute-sulfuric-acid membrane and continuous oxygen at 60–120 °C and pressures to roughly 35 bar, with a high-purity requirement that no metal ions leach from the seal; FKM is favored on the stack side for its low hydrogen permeation and oxygen resistance, and PTFE serves the low-bolt-load, high-purity areas.
In an alkaline (AEL) or anion-exchange-membrane (AEM) electrolyzer the environment is hot caustic: potassium hydroxide (KOH) at 3–30 wt% (up to 20–40%), 60–150 °C, and oxygen at 35–40 bar. EPDM has proven effective in the alkaline environment, and PTFE and expanded PTFE (ePTFE) tolerate the continuous KOH-and-oxygen contact.
The rule that keeps the paperwork honest is the same as the fuel-cell rule: ISO 22734-1 evaluates the hydrogen generator, the listing belongs to the tested system, and chemical resistance is validated per the vendor TDS (ASTM D471).
Balance-of-plant enclosure: sealing, EMI, and thermal around the stack
A stationary fuel-cell or electrolyzer system is more than its stack: around it sit the DC/DC converters, inverters, controls, and cabinets that turn the stack into usable power, and those enclosures carry the ordinary material problems of any power-electronics box. Environmental gaskets keep dust and water out to an IEC 60529 IP target; conductive EMI gaskets keep the switching noise of the power conversion contained; and thermal-interface and gap-filler pads carry heat off the semiconductors.
A breathing enclosure that cycles daily can add a ePTFE vent membrane to equalize pressure while blocking liquid water. These are the same families H-O converts for switchgear and drive enclosures; the deep versions of the dielectric, EMI, and thermal decisions live on the sibling pages, and this zone is the hydrogen-BOP edition that ties them to the stack. Frame the IP target, the EMI requirement, and the thermal path; the enclosure rating belongs to the complete enclosure, and material values are per the TDS.
Cryogenic / liquid-hydrogen seals: below every elastomer's floor
Liquid hydrogen boils near −252.9 °C, colder than liquid nitrogen (−196 °C) or liquid oxygen (−183 °C), and at that temperature the sealing problem changes completely: every common elastomer is well below its glass transition and goes glassy and brittle. FKM is one of the worst in the cold (useful only to about −20 °C), and silicone, the best of the elastomers, still bottoms out near −50 to −60 °C.
So the cryogenic seal is a fluoropolymer, not an elastomer. Expanded PTFE (ePTFE) gasket sheet holds to about −269 °C per the maker TDS and stays chemically inert across the range; virgin PTFE serves flange and low-bolt-load joints to about −200 °C; and PCTFE (the classic cryogenic valve-seat fluoropolymer) is commonly rated to about −240 °C per fabricator data for valve seats in liquid-oxygen and liquid-hydrogen service.
Where thermal contraction on cooldown would otherwise drop the contact load, a spring-energized PTFE seal restores it. One caution stays on every drawing: no blanket "leak-proof" or "hydrogen-safe" claim; low-temperature limits and compatibility are per the vendor TDS, and hydrogen embrittlement is a metals concern (the tank and fittings), not a failure mode of these polymer seals.
Cryogenic pipe & vessel insulation: keeping heat leak and boil-off down
Because liquid hydrogen is so cold, even a small heat in-leak through a gap, flange, support, or penetration produces continuous boil-off, so the whole point of the insulation is to minimize that leak. Cellular glass (for example FOAMGLAS®) is the rigid, dimensionally-stable pipe and vessel insulation: a closed-cell glass structure rated from about −268 °C, with less than 0.2% moisture absorption and non-combustible behavior (ASTM E136), which covers liquid-hydrogen temperature with margin.
ArmaGel® DT aerogel blanket is the conformable, dual-temperature wrap for fittings, elbows, and flanges: a flexible aerogel rated to about −196 °C with a low thermal conductivity near 0.015 W/m·K at −129 °C per its data sheet, to the fitting (note its −196 °C floor is a cryogenic-adjacent wrap, not a liquid-hydrogen-contact insulation by itself).
In the vacuum annulus of a jacketed line, multi-layer insulation (MLI) of alternating reflector and spacer layers is the best-performing insulation at high vacuum, and those reflector and spacer layers are themselves sheet.
H-O cellular-glass sections, aerogel-blanket wraps, and MLI reflector / spacer layers to the drawing. This page uses only cellular glass, PTFE, expanded PTFE, and the ArmaGel® line for cryogenic insulation.
Six decisions that drive your hydrogen & cryogenic seal spec
A hydrogen seal or cryogenic insulation is a single-purpose layer chosen against one controlling variable, and the failure is rarely immediate: a seal degrades in the acidic membrane, an elastomer goes brittle in the cold, a permeation number was never validated, or a listing review stalls on a material nobody can document.
Choose by environment and temperature; validate hydrogen compatibility per the vendor TDS. There is no "hydrogen-proof" elastomer. Select the seal from its chemical environment (acidic PEM membrane, hot caustic KOH, humidified gas) and its temperature window, then validate hydrogen permeation and, where pressure cycles fast, rapid gas decompression per the vendor TDS.
Cite material properties and classes by TDS, and system standards (IEC 62282, CSA/ANSI FC 1, ISO 22734-1) by designation. Never let a drawing imply a gasket is "IEC 62282 certified": the listing belongs to the tested stack or system.
Liquid hydrogen boils near −252.9 °C, colder than liquid nitrogen or oxygen. FKM is useful only to about −20 °C and silicone to roughly −50 to −60 °C, so the cold seal is a PTFE-family fluoropolymer (ePTFE to about −269 °C, PTFE to about −200 °C, PCTFE valve seats to about −240 °C per the vendor / fabricator TDS), and the insulation is cellular glass or ArmaGel® DT to the fittings.
Selection shorthand. Chemistry first, then temperature, then hydrogen compatibility per the vendor TDS. The cryogenic seal is always a PTFE-family fluoropolymer, never an elastomer.
Read the six factors below in order. The first three set the seal chemistry, temperature, and hydrogen compatibility; the next two cover the seal geometry and the balance-of-plant integration; the last one keeps the cryogenic insulation and boil-off in check. Every factor names its test method, because in hydrogen and cryogenic work the documentation is part of the part.
Show all 6 selection factors tap to expand
Chemical environment: match the seal to the media, not to "hydrogen"
Rule — pick the elastomer from the fluid it actually contacts. The PEM membrane is acidic (pH ~4–6) with continuous humidified gas, so EPDM (acid-resistant, stable after long 80 °C immersion) leads and silicone stays off the wet face, where it hydrolyzes. The alkaline electrolyzer is hot KOH, so EPDM and PTFE/ePTFE lead. The PEM electrolyzer is oxygen-rich, so FKM leads on the stack side. Name the media and concentration on the drawing (humidified H2/air, KOH %, coolant), and the family falls out of the chemistry. [10]
Temperature window: the elastomer floor is the cryogenic decision
Rule — bracket the service temperature with the material's published limits, and remember the cold end. LT-PEM seals run about −30 to +90 °C, HT-PEM 120–180 °C, and cryogenic service reaches −253 °C. FKM's cold limit is only about −20 °C and silicone's about −50 to −60 °C, so anything cryogenic moves to a PTFE-family fluoropolymer (ePTFE to about −269 °C, PTFE to about −200 °C). State the low and high service temperatures; low-temperature brittleness is tested per ASTM D2137. [3]
Hydrogen compatibility: permeation and RGD are validated, not assumed
Rule — treat hydrogen compatibility as a number to validate, never a blanket claim. Hydrogen permeates elastomers at a material-specific rate (the measured diffusion ordering is EPDM faster than NBR faster than FKM), so permeation causes loss and a safety consideration that must be simulated and validated per application.
Where pressure cycles fast, rapid gas decompression (RGD) can blister a seal from within. State any permeation or RGD requirement to evaluate per CSA/ANSI CHMC 2 (polymers in compressed hydrogen) and ISO 23936-2 (elastomer RGD), and the vendor TDS. [2]
Seal geometry: stack gasket, subgasket film, or energized cold seal
Rule — let the joint pick the form. A bipolar-plate stack seal is a gasket specified by compression and set (ASTM D395, F36); an MEA edge frame is a thin laminated PEN / polyimide film (~12–125 µm) to the window; a cryogenic flange is an ePTFE or PTFE gasket; and a cryogenic dynamic or thermally-contracting joint is a spring-energized PTFE seal, where the spring restores the contact load the cold takes away. Send the joint geometry, bolt or closure load, and film gauge; the form follows. [1]
Balance-of-plant: the enclosure is an IP, EMI, and thermal problem
Rule — spec the enclosure around the stack like any power-electronics box. Environmental gaskets to an IEC 60529 IP target (silicone for wide temperature and flame, EPDM outdoors), conductive EMI gaskets for the power conversion, insulating thermal-interface pads for the semiconductors, and a ePTFE vent membrane where a sealed cabinet would condense inside. Frame the IP target, the EMI requirement, and the thermal path; the enclosure rating belongs to the complete enclosure, and the deep versions live on the sibling pages.
Cryogenic insulation: close the heat leak, keep boil-off down
Rule — pick the insulation by form and temperature, and keep it dry and closed-cell.
Cellular glass (rated from about −268 °C, closed-cell, zero moisture, non-combustible) is the rigid pipe and vessel insulation; ArmaGel® DT aerogel blanket (to about −196 °C) is the conformable wrap for fittings and flanges; and MLI reflector / spacer layers are the vacuum-annulus answer. Send the insulation geometry and penetration detail; conductivity is per ASTM C177 and surface burning per ASTM E84.
Never spec a killed aerogel line; use cellular glass, PTFE, ePTFE, or ArmaGel®. [5]
Hydrogen & cryogenic seal failures you can prevent at spec
Hydrogen and cryogenic parts fail quietly first: a seal that degraded in the acidic membrane, an elastomer that went brittle in the cold, a permeation number nobody validated, an insulation that got wet, or a listing review that stalled on an undocumented gasket. Five patterns cover most of what goes wrong, and each is a specification decision made before the first part is cut.
In hydrogen systems, the compatibility data is part of the part. A correct material with an unvalidated permeation number, or a drawing that claims a system listing for a gasket, costs more schedule at review than any cutting error. Validate compatibility per the vendor TDS, cite material properties by TDS and system standards by designation, and keep hydrogen embrittlement in the metals lane.
Show all 5 failure modes tap to expand
1. A silicone stack gasket that hydrolyzed in the acidic membrane
Fix — keep silicone off the wet PEM face and specify EPDM (or FKM where its chemistry fits) for the membrane-contact gasket. A fuel-cell stack sealed with silicone on the acidic membrane face de-crosslinks by acid hydrolysis: weight loss and surface cracking grow with acid concentration and thermal cycling, and the seal relaxes months later. EPDM is acid-resistant and stable after long immersion at 80 °C, with better water and gas sealing than silicone; FKM suits designs where its temperature and chemistry fit.
Reserve silicone for dry-side and balance-of-plant positions, and validate the choice against the membrane chemistry on the vendor TDS. [10]
2. An elastomer seal that went glassy at cryogenic temperature
Fix — use a PTFE-family fluoropolymer for any cryogenic joint, not an elastomer. A cryogenic flange sealed with an elastomer picked for its chemistry fails cold: FKM is brittle below about −20 °C and even silicone bottoms out near −50 to −60 °C, so at liquid-hydrogen temperature the seal is glassy and leaks.
Specify expanded PTFE (to about −269 °C per the maker TDS) or virgin PTFE (to about −200 °C) for the flange, PCTFE for valve seats, and a spring-energized PTFE seal where thermal contraction would drop the contact load.
Read the low-temperature limit off the TDS and bracket the service temperature; brittleness is tested per ASTM D2137. [6]
3. A hydrogen permeation number that was assumed, not validated
Fix — validate permeation and rapid gas decompression per the vendor TDS, and never write "hydrogen-safe" on the drawing. Hydrogen diffuses through elastomers at a material-specific rate (EPDM faster than NBR faster than FKM by measured diffusion coefficient), so a seal chosen without its permeation data can lose hydrogen and raise a safety question that only shows up in test. In high-pressure cycling, rapid gas decompression can blister a seal from within.
State the permeation and RGD requirements and evaluate them per CSA/ANSI CHMC 2 and ISO 23936-2 and the vendor TDS; keep hydrogen embrittlement out of the seal discussion, because it governs the metal tank and fittings, not the polymer. [11]
4. A cryogenic insulation that got wet and drove boil-off
Fix — specify closed-cell, low-moisture, non-combustible insulation to fit the penetrations, and add MLI in the vacuum annulus. A cryogenic line insulated with an open-cell or discontinuous material admits heat and moisture: water migrates to the cold surface, ice forms, the thermal path shorts, and boil-off spikes.
Cellular glass (rated from about −268 °C, less than 0.2% moisture absorption, non-combustible) holds its performance because it is closed-cell and impermeable; ArmaGel® DT aerogel blanket wraps the fittings and flanges to about −196 °C; and MLI reflector / spacer layers carry the vacuum-annulus duty.
Die-cut the insulation to the elbow, flange, and penetration so there is no open gap for heat and water. Never substitute a killed aerogel line. [5]
5. A stack listing review that stalled on an undocumented gasket
Fix — cite material properties by TDS and system standards by designation, and let the listing belong to the tested stack. A drawing that claims "IEC 62282 certified" or "ISO 22734 listed" for a gasket stalls the review, because IEC 62282, CSA/ANSI FC 1, and ISO 22734-1 evaluate the stack or system, not a component material. Write the material's own properties and classes on the part callout, cite the system standard by designation, and supply the TDS and lot-code traceability so the OEM's qualification file is complete.
The gasket supports a design evaluated to the standard; the listing belongs to the tested assembly, and H-O does not certify systems. [15]
Specification Tools
Two tools to take you from "we're building a hydrogen or cryogenic part" to here's the material checklist for the drawing set: a requirement-driven material-stack checklist that assembles the layer list with its citations, and a side-by-side comparison of every family on this page.
1. Hydrogen & cryogenic material-stack checklist builder
Check the requirements your design carries. The builder assembles the corresponding material layers into a checklist with the family, what to send with the drawing, and the citation language (material properties per TDS; system standards by designation, listing with the tested stack or system). The default selection is pre-built for a typical PEM fuel-cell stack; every layer is also printed in the material reference section, so nothing here exists only behind a script.
Material stack checklist: 3 layers selected
Each checked requirement adds its layer below. The list is the starting bill of materials for the engineering review, not a certification: material properties come from the grade TDS, hydrogen compatibility is validated per the vendor TDS, and system standards (IEC 62282 / CSA/ANSI FC 1 / ISO 22734-1) are cited by designation with the listing belonging to the tested stack or system.
- Stack gasket: EPDM (or FKM where chemistry/temperature fit)Send: membrane chemistry, temperature window, closure / bolt load, gasket geometry. Cite: acid resistance and compression set per ASTM D395 on the TDS.
- Subgasket / edge frame: PEN or polyimide film (~12–125 µm)Send: MEA window and outer-edge geometry, film gauge, lamination need. Cite: dielectric methods per the maker TDS (ASTM D149).
- Hydrogen compatibility: validate permeation / RGD per TDSSend: pressure, cycle profile, any permeation or RGD requirement. Cite: CSA/ANSI CHMC 2 and ISO 23936-2 per the vendor TDS. No blanket "hydrogen-safe" claim.
2. Side-by-side: hydrogen & cryogenic family comparison matrix
Every family called out on this page, with construction, the property that drives its selection, the standards its TDS cites, and the zone it serves. Click a column header to sort. Click any material name to jump to its accordion entry.
| Material | Construction | Selection property | Standards on the TDS / by designation | Zone | |
|---|---|---|---|---|---|
| Fuel-cell & electrolyzer elastomers | |||||
| EPDM (foam & solid)Acid- / caustic-resistant elastomer | EPDM elastomer | Chemical environment (acid / KOH) | ASTM D395; D471 (per TDS) | Fuel cell + electrolyzer | |
| FKM / Fluoroelastomer (Viton)Chemical / low-permeation elastomer | Fluoroelastomer | Low H2 permeation / chemistry | ASTM D2240; D471 (per TDS) | Fuel cell + PEM electrolyzer | |
| Silicone (VMQ) & fluorosiliconeWide-temp / dry-side sponge & solid | Silicone sponge / solid | Temperature range (off wet face) | ASTM D1056; UL 94 (per TDS) | Fuel-cell dry side + BOP | |
| PEN / polyimide subgasket filmThin edge-frame film | PEN / PET / polyimide film | Film gauge (~12–125 µm) | ASTM D149 (per TDS) | MEA subgasket / edge frame | |
| Fluoropolymers & cryogenic insulation | |||||
| Expanded PTFE (ePTFE) gasket sheetInert cryo / caustic gasket | Expanded PTFE sheet | Temperature + inertness | ASTM F36; D2137 (per TDS) | Electrolyzer + cryogenic | |
| Virgin PTFE (film & sheet)Inert low-bolt-load / cryo gasket | Skived PTFE | Inertness + cold service | ASTM D149; per TDS | Electrolyzer + cryogenic | |
| Cellular glass insulationRigid closed-cell insulation | Cellular glass block / section | Cryo temp + zero moisture | ASTM C552; C177; E136 (per TDS) | Cryogenic insulation | |
| ArmaGel® DT aerogel blanketConformable dual-temp blanket | Flexible aerogel blanket | Low conductivity (conformable) | ASTM C177; C1728; C411 (per TDS) | Cryogenic insulation | |
Skip ahead and request your engineering review now
If your drawing set already calls out an EPDM or FKM stack gasket, a PEN / polyimide subgasket, an expanded-PTFE cryogenic gasket, or a cellular-glass or ArmaGel® insulation die-cut, send it over for engineering review against the TDSs and the standards language.
Material reference
Detailed specs for the eight families referenced on this page: the fuel-cell and electrolyzer elastomers (EPDM, FKM/fluoroelastomer, silicone and fluorosilicone) and the subgasket film (PEN / polyimide); and the fluoropolymers and cryogenic insulation (expanded PTFE, virgin PTFE, cellular glass, and ArmaGel® DT aerogel blanket).
Values are per the maker TDS on file for each grade with the method named; hydrogen compatibility is validated per the vendor TDS; system standards are cited by designation, with the listing belonging to the tested stack or system. H-O die-cuts, kiss-cuts, slits, laminates, and kits every family to drawing.
EPDM (Foam & Solid)Fuel-cell & alkaline-electrolyzer gaskets · acid- and KOH-resistant · ASTM D395 / D471 per TDS
Match the compression class to the real closure or bolt load, and validate the media compatibility on the vendor TDS. Hydrogen permeation is validated per application; no blanket "hydrogen-safe" claim.
FKM / Fluoroelastomer (Viton®)Fuel-cell & PEM-electrolyzer seals · low H2 permeation, broad chemistry · per TDS
FKM is favored where oxidation resistance and low hydrogen permeation matter; permeation and rapid gas decompression are validated per the vendor TDS, not assumed. No blanket "hydrogen-safe" claim.
Silicone (VMQ) & Fluorosilicone (FVMQ) Sponge / SolidBOP enclosure & dry-side gaskets · wide temperature, flame class · per TDS
Use silicone for temperature and flame on the enclosure and dry side; keep it off the acidic membrane face, where EPDM or FKM belongs. Values per the grade TDS.
PEN / Polyimide Subgasket & Edge-Frame FilmMEA edge protection & sealing plane · ~12–125 µm · ASTM D149 per TDS
Send the MEA window and outer-edge geometry and the film gauge; the frame is and laminated to the drawing. Dielectric methods per the maker TDS.
Expanded PTFE (ePTFE) Gasket SheetElectrolyzer & cryogenic flange gaskets · ~−269 to +315 °C per TDS · ASTM F36
The strongest branded cryogenic low end in this set; confirm the specific grade's range on the maker TDS. Die-cut edges matter: a clean, accurate flange gasket seats where a field-trimmed one leaks.
Virgin PTFE (Skived Film & Sheet)Low-bolt-load & cryogenic gaskets · ~−200 to +260 °C · inert · per TDS
PTFE stiffens as it cools but stays functional cold; for the deepest cryogenic flange, ePTFE holds a lower published low end. Cold-flow / creep is a design consideration under sustained bolt load.
Cellular Glass InsulationCryogenic pipe & vessel insulation · from ~−268 °C, non-combustible · ASTM C552
The rigid cryogenic pipe / vessel insulation of record. Die-cut to the elbow, flange, and penetration so no open gap admits heat or water. Values per the maker TDS.
ArmaGel® DT Aerogel BlanketConformable cryogenic-adjacent insulation · to ~−196 °C · ASTM C177 / C1728
ArmaGel® DT is the cryogenic / dual-temperature grade; ArmaGel® HT is high-temperature only and is not a cryogenic product. H-O also carries Aspen Cryogel® Z (cryogenic, ASTM C1728 Type I) and Pyrogel® XTE (650 °C) blankets and Blueshift AeroZero® films. Values per the Armacell TDS.
Insulating Thermal Interface Pads & Films (Sil-Pad, Gap-Pad, Secure / Protect)Heat transfer with dielectric isolation · ASTM D5470 + D149 per TDS
Compare grades per ASTM D5470 at the same pressure, and keep the dielectric requirement explicit on the drawing. Values per the TDS on file.
AeroZero® Polyimide-Aerogel Film (Blueshift)MLI layer stock & thin thermal breaks · cryo-adjacent hardware
- AZ-TPS 100 · AZ-TPS 101 single- and double-sided silicone-PSA aerogel film, 190–216 µm, UL 94 VTM-0
- AZ-TPS VDA PI 100 vapor-deposited-aluminum reflective face, 240 µm, UL 94 VTM-0 — turns back radiant load (IR reflectivity 0.94 per manufacturer data)
- AZ-TPS 102 / 103 / 104 low-outgassing acrylic-adhesive configurations, ASTM E595 TML <1% / CVCM <0.1% — the acrylic system carries a lower temperature ceiling than silicone grades, verify on the TDS
- AZ-TPS PI 100 polyimide-faced aerogel film, 240 µm, UL 94 VTM-0 — durable outer skin for handling and wear
Hydrogen & cryogenic sealing: engineer-grade FAQ
Twelve of the questions we hear most from fuel-cell, electrolyzer, and cryogenic teams. If your question isn't here, send a drawing or call, engineering picks up.
Are these materials hydrogen-safe or hydrogen-certified?
No honest supplier makes a blanket "hydrogen-safe" claim, and no material is "hydrogen-certified" on its own. Hydrogen compatibility is a set of validated properties, not a label: hydrogen permeates elastomers at a material-specific rate, and in fast pressure cycling rapid gas decompression can blister a seal, so both are simulated and validated per application per CSA/ANSI CHMC 2 (polymers in compressed hydrogen) and, for elastomer decompression, ISO 23936-2, against the vendor TDS.
System listings (IEC 62282, CSA/ANSI FC 1, ISO 22734-1) belong to the tested stack or system. What the materials carry is their own documentation and the compatibility data on file. [2]
What goes between the bipolar plates in a PEM fuel-cell stack?
A gasket that holds the humidified hydrogen and air apart and seals the coolant, plus, inside it, a thin subgasket that frames the membrane electrode assembly. The gasket is EPDM (acid-resistant, good water and gas sealing) or FKM where its temperature and chemistry fit; silicone stays off the wet acidic membrane face, where it hydrolyzes. The subgasket is a thin PEN or polyimide film (~12–125 µm) laminated to the MEA edge. The stack-checklist builder on this page assembles the layer list. [10]
EPDM vs FKM vs silicone: which goes in a PEM stack, and why not silicone?
EPDM leads the membrane-contact gasket: it is acid-resistant and stays stable after long immersion at 80 °C, with better water and gas sealing than silicone. FKM suits stack positions where its chemistry and temperature fit and lower hydrogen permeation is wanted, though its cold limit is about −20 °C.
Silicone is kept off the wet acidic membrane face because it de-crosslinks by acid hydrolysis in the fuel-cell fluoride / acid environment; it is a dry-side and balance-of-plant material here. Validate the choice against the membrane chemistry on the vendor TDS. [10]
What is a subgasket or edge frame, and what film is it?
A subgasket (edge frame) is a thin polymer film and laminated around the membrane electrode assembly. It protects the fragile membrane edge from compression and reactant-gas crossover pressure, sets the plane the stack gasket seals against, and prevents edge shorting. The common frame films are polyethylene naphthalate (PEN) and polyester (PET), roughly 12–125 µm thick (often 25–75 µm); polyimide serves where higher temperature endurance or a dielectric class is wanted. H-O and laminates the frame to the MEA window and outer edge. [12]
What seals a PEM electrolyzer versus an alkaline (KOH) electrolyzer?
Different chemistry, different seal. A PEM water electrolyzer is acidic and oxygen-rich at 60–120 °C and up to about 35 bar, with a high-purity requirement; FKM is favored on the stack side for low hydrogen permeation and oxygen resistance, and PTFE serves the low-bolt-load, high-purity areas.
An alkaline or AEM electrolyzer is hot KOH (3–30 wt%, up to 20–40%) at 60–150 °C with oxygen at 35–40 bar; EPDM has proven effective there, and PTFE and expanded PTFE tolerate the continuous KOH-and-oxygen contact. ISO 22734-1 evaluates the generator; the listing belongs to the tested system. [8]
Does hydrogen embrittle these seals?
No: hydrogen embrittlement is a metals phenomenon. Hydrogen enters the metal lattice and degrades the mechanical properties of susceptible alloys, which is why embrittlement governs the metal tank, piping, fittings, and fasteners. Polymers and elastomers are resistant to hydrogen embrittlement, so it is not a failure mode for the EPDM, FKM, PTFE, ePTFE, PCTFE, cellular-glass, or aerogel materials H-O converts.
For those polymer parts the hydrogen concern is permeation and, under fast decompression, rapid gas decompression, both validated per the vendor TDS. This is why the page stays in the elastomer / seal / insulation lane. [16]
What gasket works at liquid-hydrogen temperature?
A PTFE-family fluoropolymer, not an elastomer. Liquid hydrogen boils near −252.9 °C, well below the floor of every common elastomer (FKM to about −20 °C, silicone to about −50 to −60 °C), so at that temperature elastomers are glassy and leak.
Expanded PTFE gasket sheet holds to about −269 °C per the maker TDS and covers liquid-hydrogen temperature with margin; virgin PTFE serves flange and low-bolt-load joints to about −200 °C; PCTFE is the classic cryogenic valve-seat fluoropolymer; and a spring-energized PTFE seal restores the contact load thermal contraction takes away.
Low-temperature limits are per the vendor TDS. [6]
PTFE vs PCTFE vs expanded PTFE in the cold: which and where?
By joint. Expanded PTFE (ePTFE) gasket sheet is the cryogenic flange gasket: inert, conformable, to about −269 °C per the maker TDS, with better creep resistance than skived PTFE. Virgin PTFE handles flange and low-bolt-load joints to about −200 °C and doubles as a dielectric and low-friction layer, though cold flow under sustained bolt load is a design consideration.
PCTFE is the valve-seat fluoropolymer, commonly rated to about −240 °C per fabricator data for liquid-oxygen and liquid-hydrogen valve seats. Confirm the specific grade's low-temperature limit on the vendor TDS. [7]
Do you offer aerogel for cryogenic insulation?
Yes, ArmaGel® is the aerogel line H-O carries and converts, and ArmaGel® DT is its cryogenic / dual-temperature grade, rated to about −196 °C with a low thermal conductivity near 0.015 W/m·K at −129 °C per the Armacell TDS, to elbows, flanges, and fittings. ArmaGel® HT is a high-temperature grade, not a cryogenic product.
Because its −196 °C floor sits above liquid-hydrogen temperature, ArmaGel® DT is a cryogenic-adjacent wrap paired with cellular glass on the cold line, not a liquid-hydrogen-contact insulation by itself.
For cryogenic insulation this page uses only cellular glass, PTFE, expanded PTFE, and the ArmaGel® line. [4]
How is cellular glass used on a liquid-hydrogen line?
As the rigid pipe and vessel insulation. Cellular glass is a closed-cell glass structure rated from about −268 °C, which covers liquid-hydrogen temperature with margin; it absorbs less than 0.2% moisture, is non-combustible (ASTM E136), and is impermeable to water vapor, so it does not take on the water that forms ice and spikes boil-off on an open-cell insulation.
H-O sections, covers, and shapes to the pipe, elbow, flange, and penetration so there is no open gap for heat or moisture. Conductivity is per ASTM C177 and the cellular-glass spec is ASTM C552. [5]
Do you handle the balance-of-plant enclosure sealing, EMI, and thermal?
Yes. The cabinets, converters, and controls around a stationary fuel-cell or electrolyzer system take the same families as any power-electronics enclosure: environmental gaskets to an IEC 60529 IP target, conductive EMI shielding gaskets for the power conversion, insulating thermal-interface and gap-filler pads for the semiconductors, and a ePTFE vent membrane where a sealed cabinet would condense inside.
The deep versions of the dielectric, EMI, and thermal decisions live on the power-distribution, EMI, and power-thermal sibling pages; this page ties them to the hydrogen system, and the enclosure rating belongs to the complete enclosure.
What should I send so the quote comes back right the first time?
By zone: for the fuel-cell stack, the membrane chemistry, temperature window, closure or bolt load, gasket geometry, and MEA window and film gauge; for the electrolyzer, the media and concentration (KOH % or acidic / oxidative), temperature, and pressure; for a cryogenic part, the service temperature, flange class or valve-seat geometry, and any spring-energization need; for insulation, the pipe / fitting geometry and penetration detail.
Add any hydrogen-permeation or rapid-gas-decompression requirement to validate per TDS, the quantities for prototype and production, and the standards language you need on the paperwork (material properties per TDS; system standards by designation). "Recommend the stack" is a valid callout: that is what the engineering review is for.
Glossary: terms used on this page
Quick reference for the fuel-cell, electrolyzer, and cryogenic terminology used throughout. Each entry links to the relevant standard or test method where applicable.
PEM (proton-exchange membrane)
The acidic polymer membrane at the heart of a low- or high-temperature PEM fuel cell or PEM water electrolyzer. Its acidic, humidified environment (pH ~4–6) is why the membrane-contact gasket is EPDM or FKM, and why silicone is kept off the wet face.
Membrane electrode assembly (MEA)
The membrane, catalyst layers, and gas-diffusion layers that form the electrochemically active core of a cell. The subgasket frames and protects its fragile edge and sets the sealing plane.
Subgasket / edge frame
A thin polymer film (PEN, PET, or polyimide; ~12–125 µm) and laminated around the MEA to protect the membrane edge, set the sealing plane, and prevent edge shorting.
Electrolyzer (PEM / AEL / AEM)
A stack that splits water into hydrogen and oxygen: PEM (acidic, oxygen-rich) or alkaline / anion-exchange-membrane (hot KOH). The seal environment drives the gasket to EPDM, FKM, PTFE, or expanded PTFE, per the maker guidance [8].
Hydrogen permeation
The rate at which hydrogen diffuses through an elastomer (measured ordering EPDM faster than NBR faster than FKM). It causes hydrogen loss and a safety consideration, and is simulated and validated per application per CSA/ANSI CHMC 2 [2] and the vendor TDS. Not a "hydrogen-safe" label.
Rapid gas decompression (RGD)
Explosive decompression: dissolved gas expands when pressure drops fast and blisters or cracks an elastomer from within. The recognized elastomer test-method basis is ISO 23936-2 [17]; specified where high-pressure hydrogen cycles quickly.
Hydrogen embrittlement (metals)
Degradation of a susceptible metal's mechanical properties when hydrogen enters its lattice; it governs the metal tank, piping, fittings, and fasteners, not the polymer seals, which are resistant. See the DOE/PNNL reference [16]. Out of the seal / insulation lane.
Cryogenic / liquid hydrogen (LH2)
Liquid hydrogen boils near −252.9 °C (~20.3 K), colder than liquid nitrogen or oxygen. Below every common elastomer's floor, which is why the cold seal is a PTFE-family fluoropolymer and the insulation is cellular glass or aerogel. Storage / bulk supply are cited by CGA H-3 / H-5 [18].
Glass transition temperature (Tg)
The temperature below which an elastomer turns glassy and brittle. Silicone has the lowest useful low temperature of the common elastomers, but even it bottoms out far above liquid-hydrogen temperature; low-temperature brittleness is tested per ASTM D2137 [3].
Expanded PTFE (ePTFE)
Expanded polytetrafluoroethylene sheet gasketing: chemically inert, conformable, cryogenic (to about −269 °C per the maker TDS) to high temperature, with better creep resistance than skived PTFE. The cryogenic flange and caustic-electrolyzer gasket, per the maker data [6].
Cellular glass
Rigid closed-cell glass insulation (from about −268 °C, non-combustible, less than 0.2% moisture absorption) for cryogenic pipe and vessel surfaces; the spec is ASTM C552 [19]. Its zero moisture uptake is what keeps a cold line from icing and spiking boil-off.
Multi-layer insulation (MLI)
Alternating low-emissivity reflector and low-conductivity spacer layers used in the vacuum annulus of a jacketed cryogenic line; the best-performing insulation at high vacuum, per NASA [14]. The reflector and spacer layers are themselves sheet.
Last updated · Reviewed by H-O Products engineering (ISO 9001:2015 certified converter, Winsted, CT).
Standards, test methods & technical references
The standards, test methods, and maker technical data sheets cited throughout this page. System standards are cited by designation: they evaluate stacks, systems, and installations, and the listing belongs to the tested assembly. Hydrogen compatibility is validated per the vendor TDS. Standards editions current as of July 2026; verify against the publishing body before final spec. H-O materials are aligned to these standards through the source manufacturer's TDS, not independently certified by H-O unless explicitly stated on the quote.
[1] ASTM F36 (gasket compressibility)
Standard Test Method for Compressibility and Recovery of Gasket Materials. Short-time room-temperature compressibility and recovery of sheet-gasket materials. store.astm.org (ASTM F36)
[2] CSA/ANSI CHMC 2 (polymers in compressed hydrogen)
Test methods for evaluating material compatibility in compressed hydrogen applications — Polymers. Covers hydrogen permeation, physical-property change after hydrogen exposure, frictional wear, and contamination for polymers used in liner or sealing applications. Cited by designation. csagroup.org (CHMC 2)
[3] ASTM D2137 (low-temperature brittleness)
Standard Test Methods for Rubber Property — Brittleness Point of Flexible Polymers and Coated Fabrics. The lowest temperature at which a rubber does not fracture under specified low-temperature impact. store.astm.org (ASTM D2137)
[4] Armacell ArmaGel® DT / HT technical data
ArmaGel® DT flexible aerogel blanket (cryogenic / dual-temperature grade), service to about −196 °C with thermal conductivity per ASTM C177 and ASTM C1728 Type IV; ArmaGel® HT is a high-temperature grade only. Values per the maker TDS. armacell.com (ArmaGel DT)
[5] Cellular glass (FOAMGLAS®) technical data
Cellular glass insulation product data (Owens Corning FOAMGLAS®): rigid closed-cell glass rated from about −268 °C, less than 0.2% moisture absorption (ASTM C240), non-combustible (ASTM E136), impermeable to water vapor (ASTM E96). Values per the maker TDS. foamglas.com (FOAMGLAS)
[6] Expanded PTFE (Gore® GR) sheet gasketing data
Expanded PTFE sheet gasketing technical data (W. L. Gore GR): continuous service about −269 to +315 °C and full vacuum, chemically inert, seals in strong caustics and acids and at cryogenic temperature, with better creep resistance than skived PTFE. Values per the maker TDS. gore.com (GR sheet gasketing)
[7] Virgin PTFE gasket technical data
Virgin PTFE gasket sheet technical data: continuous service roughly −200 to +260 °C, near-total chemical inertness (attacked only by molten alkali metals and elemental fluorine at high temperature), stiffens but does not shatter cold. Values per the maker TDS. ramgaskets.com (Virgin PTFE)
[8] Sealing requirements across the hydrogen value chain (maker literature)
Freudenberg Sealing Technologies, sealing requirements for fuel cells and electrolyzers: LT-PEMFC 60–80 °C and HT-PEMFC 120–180 °C; PEM electrolyzer FKM on the stack side and PTFE for low-bolt-load / high-purity areas; alkaline electrolyzer EPDM, PTFE, and ePTFE for the KOH-and-oxygen duty; hydrogen permeation validated per application. fst.com (H2 value-chain sealing)
[9] ASTM D149 (dielectric strength)
Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies. The dielectric method behind the subgasket / film properties. store.astm.org (ASTM D149)
[10] Fuel-cell stack sealing structures & materials (peer-reviewed)
Clean Energy (Oxford Academic, 2023), review of PEM fuel-cell stack sealing structures and materials: silicone degrades by acid hydrolysis in the fuel-cell fluoride / acid environment; EPDM is acid-resistant with better water and gas sealing; fluoroelastomer's low limit is about −20 °C. academic.oup.com (Clean Energy 2023)
[11] Hydrogen permeation / diffusion in elastomers (peer-reviewed)
Scientific Reports (2021), hydrogen permeation and diffusion in elastomers: the measured permeability / diffusion ordering is EPDM greater than NBR greater than FKM, with FKM the slowest diffuser. Supports the per-material permeation framing. nature.com (Sci Rep 2021)
[12] Subgasket / edge-frame film (patent literature)
Fuel-cell subgasket patent literature (US 9,076,998 B2): the common subgasket films are PEN and PET (with polyimide where higher temperature is needed), with frame thickness about 12–125 µm (preferably 25–75 µm). patents.google.com (US9076998B2)
[13] PCTFE cryogenic valve-seat data (fabricator)
PCTFE (polychlorotrifluoroethylene) fabricator data: commonly rated to about −240 °C for cryogenic valve seats in liquid-oxygen and liquid-hydrogen service; retains a bubble-tight seal without shattering. The specific low-temperature rating is per the vendor TDS (the base-resin datasheet may not publish one). polymerplastics.com (PCTFE)
[14] Multi-layer insulation for cryogenic systems (NASA)
NASA technical literature on multi-layer insulation (MLI) for cryogenic systems: MLI, alternating low-emissivity reflector and low-conductivity spacer layers, is the best-performing cryogenic insulation system at high vacuum. ntrs.nasa.gov (MLI performance)
[15] CSA/ANSI FC 1 & IEC 62282 (fuel-cell systems, by designation)
CSA/ANSI FC 1, Stationary fuel cell power systems (adopting IEC 62282-3-100), and the IEC 62282 fuel-cell-technologies series (fuel cell modules and stationary power systems, safety). Cited by designation; the listing belongs to the tested stack or system. csagroup.org (CSA/ANSI FC 1)
[16] Hydrogen embrittlement is a metals phenomenon (DOE/PNNL)
U.S. DOE / PNNL H2tools, Hydrogen Embrittlement: hydrogen in the metal lattice degrades the mechanical properties of susceptible alloys; the phenomenon governs metal tanks, piping, and fittings. Polymers are resistant, which is why the page keeps embrittlement out of the seal / insulation discussion. h2tools.org (Hydrogen Embrittlement)
[17] ISO 23936-2 (elastomer rapid gas decompression)
ISO 23936-2, Non-metallic materials in contact with media related to oil and gas production — Part 2: Elastomers. The recognized test-method basis for the effect of rapid gas decompression (explosive decompression) on elastomer seals; cited as the RGD reference. iso.org (ISO 23936-2)
[18] CGA H-3 / H-5 & NFPA 2 (cryogenic & bulk hydrogen, by designation)
Compressed Gas Association CGA H-3 (cryogenic hydrogen storage) and CGA H-5 (bulk hydrogen supply systems), and NFPA 2 (Hydrogen Technologies Code), cited by designation as the cryogenic and bulk-hydrogen system context. cganet.com (CGA H-5)
[19] ASTM C552 & C177 (cellular glass & thermal transmission)
ASTM C552, Standard Specification for Cellular Glass Thermal Insulation (surfaces to about −268 °C), and ASTM C177, steady-state thermal transmission by guarded hot plate (the method behind the insulation conductivity values). Surface burning is ASTM E84. store.astm.org (ASTM C552)
Updated . Standards editions and links current at publication; verify against the publishing body before final spec. Hydrogen compatibility is validated per the vendor TDS; H-O converts materials tested to the methods cited and does not certify stacks or systems. Lot-specific documentation available on request.
To review your hydrogen or cryogenic seal design, send:
- Sub-system (fuel-cell stack, electrolyzer, BOP, or cryogenic / LH2)
- Media and concentration (humidified H2 / air, KOH %, coolant, LH2)
- Temperature window (and any cold-start floor)
- Any hydrogen-permeation or RGD requirement to validate per TDS
- Gasket / bipolar-plate seal geometry or flange class
- Bolt or closure load / compression window
- MEA window and subgasket film gauge (if applicable)
- Insulation geometry and penetration detail (if applicable)
- Adhesive / liner / lamination requirements
- Prototype and annual volume
Get a hydrogen & cryogenic sealing engineering quote
Send a drawing set, BOM, or stack spec. We typically respond within one business day with a material recommendation, prototype lead time, and TDS verification against your chemical environment, temperature window, hydrogen-compatibility requirement, and standards language.
See also: related H-O application pages
Engineering content for the adjacent energy sub-applications and the parent hub. Each page covers material selection, failure modes, and converter-side process detail for its application family.
Sibling sub-application
Busbar, transformer & power distribution insulation
The dielectric film, aramid paper, and laminate playbook behind this page's balance-of-plant power electronics, across the distribution voltage range.
Read the page
Sibling sub-application
Energy chemical, oil & fluid sealing
The chemical- and fluid-service sealing playbook, including spring-energized PTFE and FKM/FFKM gaskets, that this page's cryogenic and electrolyzer seals draw from.
Read the page
Sibling sub-application
Nuclear & small modular reactor (SMR)
The high-integrity seal, gasket, and barrier material story for advanced nuclear and SMR equipment, another blue-ocean energy application family.
Read the page
Industry hub
Energy, power & renewable
The full energy application family: power distribution, thermal, EMI, sealing, arc-flash, vibration, hydrogen, and nuclear, with the material catalog this page draws from.
Read the page
Material data & standards. All temperature, chemical, and dielectric values on this page are taken from the source maker's technical data sheets with the method named (ASTM D2240, D412, D395, D471, F36, D2137, D149, C552, C177, E84; UL 94 classes per the listed grade TDSs). Hydrogen compatibility (permeation, rapid gas decompression) is validated per application per CSA/ANSI CHMC 2 and ISO 23936-2 and the vendor TDS; no blanket "hydrogen-safe" or "leak-proof" claim is made.
System standards (IEC 62282, CSA/ANSI FC 1, ISO 22734-1, ISO 14687, ISO 19880-1, NFPA 2, CGA H-3, CGA H-5) are cited by designation only: they evaluate stacks, systems, and installations, the listing belongs to the tested assembly, and the materials on this page support designs evaluated to them. Hydrogen embrittlement is a metals concern (tanks, piping, fittings), not a failure mode of the polymer seals and insulation H-O converts.
H-O converts materials; H-O does not manufacture stacks, design fuel-cell or electrolyzer systems, or certify systems, and does not independently certify materials unless explicitly stated on the quote. Verify against the maker TDS and your system-level evaluation plan.
Conversion scope. H-O and converts sheet, roll, and blanket stock to drawing in Winsted, Connecticut: die-cut and kiss-cut gaskets and seals, laminated subgasket / edge frames, slit films, waterjet-cut thick sections, insulation die-cuts, and kitted stack-seal sets, with material traceability and lot-code TDS records. H-O does not mold or run extrusion lines; molded or extruded profiles are coordinated through a partner network.
For cryogenic insulation this page uses only cellular glass, PTFE, expanded PTFE, and the ArmaGel® line. Lead-time and MOQ details are in the process strip and the quote form above.