Helium is the hardest gas in industrial use to keep inside a vessel. Its atoms are the second-smallest that exist, it permeates polymers at roughly two to three times the rate of hydrogen, and it escapes through paths no other gas finds — which is exactly why leak-test engineers use it as their tracer gas. So when we say our sealed liner shows no measurable permeation with helium — verified with helium leak detection, the most sensitive escape measurement in industrial practice — we are reporting the hardest test we could run on a composite cylinder. The result: MEYER hydrogen and helium cylinders now hold the un-holdable, at 2.8 kg where metal answers weigh 8–9 kg, with no limited lifespan. Here is what that unlocks, market by market.

Why a lightweight helium cylinder was impossible — until now

A Type IV cylinder — polymer liner, carbon-fibre overwrap — wins every weight comparison there is. But the polymer liner is the gas barrier, and against helium, polymers leak: where a thin-lined composite cylinder loses hydrogen at rates measured in tens of percent per month, helium goes faster still. For applications that fill in the morning and use the gas by evening, that never mattered. For applications that need helium to stay — a pressurant sphere in orbit, a topping cylinder on an airship mast, a tracer-gas bottle between test campaigns — it disqualified composite entirely, and the market defaulted to steel and aluminium, paying for gas-tightness in kilograms.

The MEYER sealed liner closes that path. In qualification testing, cylinders built on it show no measurable loss for hydrogen or helium — below the detection threshold of helium leak-detection equipment. Model it yourself in the permeation calculator: the sealed liner sits at the Type 1 steel reference rate, in a cylinder one-third to one-quarter of the weight. And because the liner is not metal, there is no fatigue cap: the classic HDRX range keeps its NLL — no limited lifespan — rating, and every HDRX size is now available as a dedicated helium part number (-HE suffix) — HDRX-005-HE through HDRX-400-HE. The CE-certified HDRX-068-HE (6.8 L) and HDRX-400-HE (40 L) are available to order, with 120 L and 350 L sizes in development. Browse the helium segment →

Helium pressurant cylinders for satellites and launch vehicles

Helium pressurant is the quiet workhorse of propulsion: it pushes propellant out of tanks, actuates valves, and feeds cold-gas thrusters on satellites and kick stages. Two facts rule this application. First, the pressurant must still be there when the mission needs it — a station-keeping system that bleeds its helium through a polymer liner over eighteen months in orbit is a dead satellite with full propellant tanks. Second, every gram of storage is bought at launch prices — the cylinder’s mass competes directly with payload. Historically those two facts pointed in opposite directions: tightness meant metal, mass meant composite. The sealed liner ends the contradiction — composite mass, metal tightness. For ground-test and reusable-stage service, NLL cycle behaviour adds a third argument the metal-lined alternatives cannot make. Start with our launcher pressure-systems overview and CubeSat cold-gas thruster page, or run envelope trades in the mass calculator.

Helium cylinders for airships, aerostats and HAPS

Every lighter-than-air platform lives on a helium budget — envelopes breathe, fittings seep, and altitude cycling costs lift gas that must be replaced. Cargo-airship programmes, tethered aerostats and stratospheric platforms (HAPS) all need topping helium where the vehicle is: on board, at a remote mast, at an austere operating site. This is the most weight-obsessed customer in the gas business — on an airship, a kilogram of cylinder is a kilogram of lift spent carrying the cylinder. A 2.8 kg composite cylinder replacing an 8–9 kg aluminium one returns its own mass in useful lift several times over, holds its contents indefinitely thanks to the sealed liner, and its NLL rating fits fleets planned to operate for decades.

Helium tracer-gas cylinders for leak testing and industry

Helium tracer-gas testing is everywhere serious tightness is verified — automotive fuel and AC circuits, refrigeration, semiconductor tools, medical devices. And helium is expensive, supply-constrained, and increasingly rationed. That gives permeation a price tag: a tracer-gas cylinder that loses content between test campaigns is a recurring invoice, and a portable service kit built on steel is a two-person lift. Sealed-liner composite cylinders hold tracer gas without loss between uses, cut kit weight by two-thirds for field service teams, and — because helium recovery systems increasingly close the loop — make the storage side of recovery as tight as the recovery itself. The permeation calculator shows the loss-rate comparison per liner type directly.

Helium cylinders for scientific ballooning and field research

Radiosonde stations, university stratospheric programmes and field campaigns launch from wherever the science is — which is rarely next to a gas depot. Helium logistics decide what a campaign can do: cylinders are carried by truck, boat, sled and hand to remote launch sites. Cutting per-cylinder mass from ~9 kg to 2.8 kg changes how much gas a team can position per trip, and the sealed liner means the gas positioned in autumn is still there for the spring campaign. For institutional fleets, NLL removes the cylinder-retirement clock that steel and aluminium impose on procurement cycles.

The engineering summary

The honest footnote, as always: “no measurable” is a measurement statement — losses below helium leak-detection thresholds under qualification test conditions — and whole-system tightness includes your valve and fittings, which is why we offer validated cylinder–regulator development. Measured data for a specific SKU ships with the certificate documentation.

When an EOD or MCM diver works next to a magnetic-influence-fuzed sea mine, every piece of equipment on their back is a potential trigger. NATO’s answer is STANAG 2897 — the standard that promulgates AEODP-7, “Standardization of EOD Equipment Requirements” — and its Class A “non-magnetic” category: equipment with a magnetic signature low enough to be used in direct proximity to influence-fuzed ordnance. Steel cylinders can never meet it. The traditional answer has been aluminium; the better answer is carbon composite. MEYER’s HDRX cylinders are non-magnetic by construction, matt black by design, and roughly a third of the weight of the aluminium cylinders they replace.

Why magnetic signature decides what a mine-clearance diver carries

Modern sea mines don’t wait to be touched. Influence fuzes listen for the signatures of a target — acoustic, pressure, and above all magnetic: the local distortion of the Earth’s field caused by ferromagnetic material moving nearby. A diver sent to identify or neutralise such a mine must be, magnetically speaking, not there at all. That requirement flows down to every object in the water column with the diver — rebreather, tools, and the breathing-gas cylinder strapped to their back, centimetres from their body and often less than a metre from the ordnance.

STANAG 2897 (AEODP-7) formalises this: Class A (“non-magnetic”) covers equipment approved for use in direct proximity to magnetic-influence-fuzed ordnance, including sea mines. The standard also defines a lower “low-magnetic” class — but that is for equipment approved only at a stand-off distance. For a back-mounted cylinder next to a mine, Class A is the class that applies. It is the rating quoted across serious MCM/EOD diving equipment: Dräger describes its LAR 8000 rebreather as “designed and tested in accordance with STANAG 2897 Class A,” and JFD’s Stealth SC MCM apparatus is rated “non-magnetic to NATO STANAG 2897 A/AEODP-7.”

Steel never qualifies. Aluminium and titanium were the workarounds.

A standard steel cylinder is a ferromagnetic mass — no surface treatment changes that, which is why steel is structurally incapable of meeting Class A. For decades the practical procurement answer has been aluminium-alloy cylinders fitted with non-magnetic valves in bronze or Monel-type alloys. It works, but it carries costs an EOD unit feels every day:

• Weight. Aluminium cylinders are heavy for the gas they carry — a diver’s 6.8-litre aluminium cylinder sits in the 8–9 kg class before the valve. That is fatigue during long approaches, harder boat and airlift logistics, and more mass to trim underwater.
• Service life. Aluminium liners accumulate fatigue with every fill cycle.
• Visibility. Polished or painted metal reflects — moonlight, torchlight, muzzle light. For covert insertion and night operations, glint is a signature of its own.

Navies and specialist units have also fielded titanium cylinders — the premium metal route to a non-magnetic kit. Titanium deserves an honest scorecard of its own:

• Pros: genuinely non-magnetic; roughly 40% lighter than steel at equivalent strength; essentially immune to seawater corrosion, which matters over a fleet’s life in salt water; mechanically very tough.
• Cons: among the most expensive cylinder routes there is — costly raw material, specialist forming and welding, and a very small supplier base with long lead times; still in the ~5–7 kg class for a 6.8-litre cylinder, roughly twice the weight of composite; cycle life remains capped by metal fatigue like any metal-lined vessel; and titanium’s tendency to gall demands careful valve-thread engineering.

Titanium solved the magnetic problem at the highest price point in the market. It never solved the weight problem — it only softened it.

The composite answer: non-magnetic by construction

A MEYER HDRX cylinder is a Type IV composite pressure vessel: a polymer liner, aluminium-alloy bosses, and a full carbon-fibre overwrap. There is no ferromagnetic material in the pressure vessel — non-magnetic is not a treatment or a variant, it is what the cylinder is made of. Paired with a bronze/Monel-class non-magnetic valve, the complete assembly is aligned with what STANAG 2897 (AEODP-7) Class A procurement specifies for diver-carried equipment.

The differences a unit notices:

The matt-black finish deserves a word, because it is deliberate. Every HDRX cylinder leaves production in a non-reflective matt black — no bright wrap, no gloss lacquer, no high-visibility paint scheme. At night or in turbid water the cylinder does not catch light and does not draw attention. For civilian users this is aesthetics; for military and special-operations users it is the visual half of signature management, and it comes standard.

What to write in the tender

• Specify compliance with STANAG 2897 (AEODP-7) Class A non-magnetic for the complete cylinder-and-valve assembly — the cylinder alone is not the whole magnetic story; the valve must be bronze/Monel-class non-magnetic too.
• Specify the diving-service requirements alongside: underwater rating, breathing-gas compatibility, and periodic-inspection regime.
• For weight-critical procurement, compare on mass per litre of gas carried, not unit price — the composite premium repays itself in diver endurance and logistics.

One caveat worth knowing before you write acceptance criteria: STANAG 2897 / AEODP-7 is a NATO-restricted document. The exact residual-field limits — nanotesla at a defined distance, per class — are not published openly, and formal verification is performed by national military authorities with calibrated magnetometer measurements. If your tender needs the precise thresholds, they must come through your national defence standardization office or NATO EOD channels; we support that process with per-unit documentation and materials declarations on request.

The cylinders

The full HDRX range — 0.5 L to 40 L, 300 bar, TPED/CE/ISO 11119-3 qualified, UW-rated, NLL service life — is available in dedicated -MIL part numbers (non-magnetic valve, matt black, EOD/MCM configuration): HDRX-005-MIL through HDRX-400-MIL. Browse the military/UW segment directly: STANAG-class cylinders in the COPV catalog, or start with the workhorse sizes: HDRX-030-MIL (3 L), HDRX-068-MIL (6.8 L), HDRX-090-MIL (9 L). At the compact end sits the HDRX-008-MIL — 0.8 L at just 0.55 kg, 300 bar working / 450 bar test pressure, NLL, qualified to EN 12245:2009+A1:2011 with π, CE and ISO 11119-3 marking, approved for air and nitrogen, in M18×1.5, 5/8″-18 UNF or 17E threads — the suit-inflation, tool-gas and reserve size that rides alongside the diver’s main cylinder without registering on the scale or the magnetometer. For programme-specific configurations — valve material, thread, manifolding, marking — open an RFQ. Defence UAV programmes should also see our ITAR-free tactical UAV cylinder overview.

Sources

• European Security & Defence — “The right stuff below the waves” (Dräger LAR 8000, STANAG 2897 Class A)
• JFD Stealth SC datasheet — “Non-magnetic to NATO STANAG 2897 A/AEODP-7”
• GlobalSpec — NATO STANAG 2897 (AEODP-7), restricted standard listing

Status current as of July 2026. STANAG 2897 / AEODP-7 is a restricted NATO document; formal Class A verification rests with national military authorities.

Every polymer-lined Type IV cylinder leaks a little — it’s physics, not a defect. Gas dissolves into the liner, diffuses through it, and escapes: for hydrogen at 300+ bar, that has meant losses on the order of tens of percent per month through thin polymer liners; for helium, the industry’s most escape-prone gas, it has meant that composite cylinders were often ruled out entirely and missions flew heavy metal-lined tanks instead. That trade-off is what MEYER’s new sealed liner removes: no measurable hydrogen or helium permeation — verified by helium leak detection — in a MEYER cylinder for hydrogen and helium: full-composite construction with Type 1 gas-tightness, at a fifth of the weight.

The problem: permeation is the tax on lightweight storage

The classification of composite cylinders is a story of what sits between the gas and the carbon fibre. A Type 1 steel cylinder is effectively permeation-free — metal is a near-perfect gas barrier — but a 6.8-litre steel cylinder at high pressure weighs several times its composite equivalent. A Type IV cylinder wraps carbon fibre around a polymer liner and wins the weight war decisively, but the polymer is the gas barrier, and polymers are permeable:

• Hydrogen, the smallest molecule, works through thin polymer liners at rates that make long-duration storage impractical — fine for a drone that fills daily, unusable for a tank that must hold pressure for months.
• Helium is worse: roughly 2–3× the permeation rate of hydrogen through most polymers. Helium pressurant systems, leak-test rigs, balloon and airship programmes, and satellite cold-gas systems have historically had one honest answer — a metal liner, with the weight and the fatigue-limited cycle life that come with it.

We’ve published the numbers for years in our permeation calculator and the PET vs HDPE liner analysis — including the honest figure for our own classic PET-lined cylinders. The engineering trade was real: minimum mass or gas-tightness. Pick one.

What changed: the MEYER sealed liner

Our 2026 hydrogen and helium range ships with a new proprietary liner system that closes the permeation path entirely. In qualification testing, cylinders built on the sealed liner show no measurable permeation for hydrogen or helium — losses sit below the detection threshold of helium leak-detection equipment, the most sensitive gas-escape measurement in industrial use. In our permeation model, that places the sealed liner at the Type 1 steel reference rate — which is why the calculator now offers “MEYER® sealed” as a liner option alongside steel, aluminium, HDPE and PET.

What that means in cylinder terms:

The cycle-life point deserves emphasis. The traditional route to gas-tight composite cylinders — a thin metal liner (Type III, or “Type IV-M”) — buys tightness at the cost of metal fatigue, which caps pressure cycles. The sealed liner is not a metal liner: a MEYER hydrogen or helium cylinder keeps its full composite fatigue behaviour, so gas-tightness no longer costs you cycle life either.

Who this unlocks — helium first

• Helium systems, finally on composite. Pressurant storage, cold-gas propulsion, leak-test rigs, lighter-than-air programmes: applications that have carried steel or aluminium for decades can now spec a 2.8 kg cylinder instead. Every HDRX size is available as a dedicated -HE part number — see the helium range in the catalog.
• Hydrogen that stays put. A fuel-cell UAV that fills before each sortie never noticed permeation. A hydrogen system that must hold pressure across weeks — backup power, remote assets, seasonal operations — absolutely did. The HDRX-068-H2 and the 40 L HDRX-400-H2 now serve both.
• Long-duration R&D setups where a bench must sit pressurised between test campaigns without drift skewing the data.

The honest footnotes

• “No measurable” is a measurement statement, not a metaphysical one: losses are below helium leak-detection thresholds under our qualification test conditions. We publish it that way deliberately — engineers should distrust anyone claiming absolute zero.
• Whole-system tightness still depends on your valve, regulator and seals — a perfect cylinder feeding a leaky fitting still loses gas. Pair it properly: our validated cylinder–regulator development exists for exactly this reason.
• Measured permeation data for a specific SKU is available with the certificate documentation — ask when you order.

Availability

The sealed liner ships in the 2026 hydrogen (-H2) and helium (-HE) models across the range: the hydrogen 6.8 L and 40 L models (CE certified) are open for pre-order with first deliveries from mid-September, the helium range is available to order, and the 120 L and 350 L sizes are in development. Browse by gas: hydrogen · helium — or run your own numbers in the permeation calculator.

ISO/DIS 25013 is the first international standard written specifically for the hydrogen cylinders that fly on fuel-cell drones. Its full title is “Unmanned aircraft systems — General requirements and test methods for the attachable hydrogen cylinders of gaseous hydrogen fuel cell powered UAS,” and it is being developed by ISO/TC 20/SC 16, the committee for uncrewed aircraft systems and advanced air mobility. As of July 2026 it is a Draft International Standard: the DIS public-enquiry window closed on 18 June 2026 and national-body comments are now being processed. Nobody can be certified to it yet — but every serious hydrogen-UAS programme should already be designing with it in view. Here is what is public, what it changes, and what to do about it today.

Why fuel-cell UAS needed their own cylinder standard

Until now, a hydrogen tank on a drone has lived in a regulatory gap. The established composite-cylinder standards were written for other worlds:

• Transportable-cylinder standards — ISO 11119-3, EN 12245 — govern cylinders that are filled, moved and used as general gas packages. They are the workhorse certification route for UAV tanks today, but they were not written with airborne operation, flight loads or quick-swap refuelling in mind.
• Road-vehicle fuel-container standards — UN Regulation 134, ISO 19881 — assume a tank permanently mounted in a car or truck, with crash cases and fire scenarios that don’t map onto a 25-kg airframe. (If you’re navigating that family, start with our guide to what replaced the repealed EC 79.)
• Hydrogen transport standards — EN 17339 — govern the bundles and trailers that move hydrogen to your operation, not the tank on the aircraft. We’ve written a full breakdown of EN 17339.

A flight-weight hydrogen cylinder is a different engineering object from all three: it is weight-critical to the gram, it is handled far more often than a vehicle tank (swapped, recharged, transported between sites), and its failure modes matter in the air and on the ground. ISO/DIS 25013 exists because the fuel-cell-UAS industry grew big enough that “certify it as a generic transportable cylinder and hope the aviation authority accepts it” stopped being good enough.

What the public scope tells us

The draft’s published scope is short but revealing. It specifies the minimum safety, performance and integrity requirements — and the test methods to verify them — for the attachable hydrogen cylinders of gaseous-hydrogen fuel-cell powered UAS.

Two words in that scope deserve attention:

• “Attachable.” The standard is aimed at cylinders designed to be mounted to and removed from the aircraft — the swap-tank operating model, where an empty cylinder comes off and a full one goes on between sorties. That is how real fleets actually achieve availability (see our note on refuelling a drone in 90 seconds), and it is exactly the handling profile that generic cylinder standards never contemplated: repeated mounting cycles, connector wear, field handling by operators rather than gas professionals.
• “Gaseous hydrogen.” Compressed GH₂ only — liquid-hydrogen concepts are a different problem and a different (future) document.

The full technical content of the draft — design margins, test matrix, cycle counts — is available only to national mirror-committee participants and is still subject to change through comment resolution, so we won’t speculate on clause-level detail here. What is certain is the intent: a dedicated qualification path for flight-weight, operator-handled, swappable hydrogen cylinders.

Where ISO 25013 sits in the standards map

The committee behind it matters too. ISO/TC 20/SC 16 is an aviation committee — the body that standardises UAS design, operations and traffic management — not a gas-cylinder committee. The cylinder is being treated as an aircraft component, with a companion draft (ISO/DIS 25009) covering the hydrogen fuel lines that connect it to the stack. That framing is the whole point: the fuel system of a hydrogen drone is becoming certifiable equipment, not an adapted gas bottle.

Timeline: what happens next

• 18 June 2026 — DIS public-enquiry window closed; national bodies submitted votes and technical comments.
• Now — comment resolution within ISO/TC 20/SC 16. Depending on the outcome, the project proceeds to a Final Draft (FDIS) ballot or directly to publication.
• Realistically 2027 — publication as ISO 25013, if comment resolution stays on a normal track. Draft content can still change until then.

We will update this article as the project moves stages.

What a UAS programme should do today

• Buy certified against the standards that exist now. Until ISO 25013 publishes, the defensible route for a flight hydrogen cylinder is a certificate against the transportable-cylinder framework — EN 12245 / ISO 11119-3 — plus CE marking where applicable. That is a document set your aviation authority, insurer and safety officer can act on today.
• Treat “ISO 25013 certified” claims as a red flag. Nobody can be certified to a draft. A supplier who claims it either doesn’t understand the process or hopes you don’t. The honest formulation — the one we use ourselves — is designed with the draft’s intent in view, certified to the published standards.
• Design for swappability now. The draft’s focus on attachable cylinders confirms where operations are heading. Standardised mounting interfaces, quick-connect necks and swap-based refuelling are the assumptions to build into your airframe today so that an ISO 25013-qualified cylinder drops in later without a redesign.
• Follow the draft through your national body. If hydrogen UAS is core to your roadmap, your national ISO member body’s mirror committee for TC 20/SC 16 is where you can read the full draft and influence the final text.

Where MEYER stands

We build exactly the object this standard describes: flight-weight, attachable hydrogen cylinders for fuel-cell UAS. Our HDRX-068-H2 (6.8 L / 350 bar, ≈160 g H₂ at 2.8 kg) carries an issued certificate to EN ISO 12245:2022 and CE marking — the published-standards route described above — and is available for pre-order now, with the ultra-light UL variant in qualification behind it. We have contributed to composite-cylinder standardisation before, as working-group participants in CEN/TC 23/WG 16 (the group behind EN 17339), and we are tracking ISO/DIS 25013 through the same lens: when the standard publishes, our hydrogen range will be qualified against it as early as the process allows.

Specifying a hydrogen tank for a UAV right now? Start with our engineering guide, compare the full COPV range, or go straight to the HDRX-068-H2 product page for the datasheet and 3D model.

Sources

• ISO/DIS 25013 — iso.org project page
• ISO/TC 20/SC 16 — Uncrewed aircraft systems
• SFS public-enquiry record (deadline 18 June 2026)

Status current as of 14 July 2026. This article describes a draft standard; technical content may change before publication.