Product · PEX · Heating
Oxygen Barrier PEX Pipe — EVOH Layer to DIN 4726 for Hydronic Heating
Hitze is a German brand of premium oxygen-barrier PEX pipe, contract-manufactured to German standards. An EVOH barrier layer blocks oxygen diffusion per DIN 4726 — protecting boilers, pumps and manifolds from corrosion in closed heating loops.
Sized 16–25 mm, red/blue/white, bulk and private-label ready — with matching manifolds if you sell the whole loop.
Trade / wholesale supply only — Hitze supplies wet (water-based) hydronic systems, not electric floor mats, and does not sell single coils at retail.
EVOH · DIN 4726 · EN ISO 15875 The Product
See Oxygen-Barrier PEX — Layer, Coil & Loop
The EVOH barrier, the heating-grade coil, and what it protects — one German-engineered heating pipe. Studio shots below show exactly what ships.
EVOH · DIN 4726
What an Oxygen Barrier Does — EVOH Layer, DIN 4726, and Why Your Boiler Depends On It
In a closed heating loop the water recirculates for years. Every molecule of oxygen that diffuses through the pipe wall goes looking for steel to corrode. The barrier is the line of defence.
Ordinary PEX is slightly permeable to oxygen. In an open system that’s harmless — but a hydronic loop is closed, so oxygen that seeps through the wall dissolves into the water and attacks the steel and cast-iron parts it touches: boiler heat exchangers, circulating pumps, and steel/brass manifolds. Over a heating season this shows up as rust, sludge, blocked flow and premature failure. Hitze oxygen-barrier PEX embeds an EVOH (ethylene vinyl alcohol) layer bonded inside the pipe wall that limits oxygen diffusion to the DIN 4726 threshold, so the loop stays clean and the metal components last.
- The mechanism: EVOH is a high-barrier polymer laminated between PEX layers with tie-adhesive — not a surface coating that scuffs off.
- The standard: DIN 4726 sets the maximum permissible oxygen permeation for pipes in closed heating circuits; Hitze barrier PEX is built to that limit — oxygen-permeation figures coming soon.
- The alignment: also built to ASTM F876/F877 (PEX) and EN ISO 15875 — one pipe, both markets.
Barrier is a spec, not an upgrade. For any closed hydronic or radiant-floor loop, a DIN 4726 oxygen barrier is the requirement. Non-barrier PEX belongs on potable water, not heating.
Construction & Sizes
Five-Layer EVOH Build, 16 to 25 mm
A barrier is only as good as where it sits in the wall. Ours is laminated inside, protected on both faces, across the sizes radiant work actually uses.
The oxygen barrier is not painted on the surface where handling and installation would damage it. It’s laminated inside the pipe wall and protected by an outer PEX layer:
| Layer | Material | Function |
|---|---|---|
| 1 (outer) | PEX | Mechanical protection, print/branding surface |
| 2 | Tie-adhesive | Bonds barrier to outer PEX |
| 3 (core) | EVOH | Oxygen barrier — blocks O₂ diffusion per DIN 4726 |
| 4 | Tie-adhesive | Bonds barrier to inner PEX |
| 5 (inner) | PEX | Fluid contact, flow surface, pressure/temperature rating |
| Nominal size | Metric OD | SDR | Form | Colors |
|---|---|---|---|---|
| 16 mm | DN16 | SDR 9 (approx.) | Coil | Red / Blue / White |
| 20 mm | DN20 | SDR 9 (approx.) | Coil | Red / Blue / White |
| 25 mm | DN25 | SDR 9 (approx.) | Coil / straight | Red / Blue / White |
16 mm and 20 mm are the radiant-floor volume sizes; 25 mm serves distribution and larger loops. Coil lengths, bend radius and pressure/temperature ratings (bar / ℃) per size are in the Spec Pack. Exact stock coil lengths and ratings: coming soon.
Download the Oxygen-Barrier PEX Spec Pack
Five-layer construction, DIN 4726 data, dimensional table, coil lengths and pressure/temperature ratings in one PDF for your compliance and design files. Email required · test figures coming soon.
Radiant & Hydronic
Built for Radiant Floor & Hydronic Heating — And the Manifold to Match
Barrier PEX isn’t a standalone SKU — it’s one part of a loop. Buyers who sell the whole system win the margin.
Hitze oxygen-barrier PEX is engineered for wet (water-based) hydronic systems — radiant floor loops, panel-radiator circuits and closed heating distribution — not electric floor mats. The DIN 4726 barrier keeps the recirculating water oxygen-free so boilers, pumps and manifolds run clean for the life of the system. Because 16 mm and 20 mm barrier PEX pairs directly with Hitze underfloor-heating manifolds and press fittings, importers and private-label brands can ship a complete hydronic package — pipe, manifold and connections from one certified source — instead of a lone coil.
- Use barrier PEX for closed hydronic / radiant-floor heating loops.
- Use non-barrier potable PEX for domestic drinking water (see the parent PEX page).
- Sell the system: barrier PEX + manifold + press fittings, one supplier, one set of paperwork.
Building the full loop? Pair barrier PEX with our manifolds and press fittings for a single-supplier hydronic package.
Request Oxygen-Barrier PEX Samples → See Our UFH Manifolds →
Selection
Oxygen-Barrier vs Non-Barrier PEX — Which One, and When
Same base pipe, one added layer, two different jobs. Getting the choice right is the difference between a clean loop and a corroded boiler.
| Spec | Oxygen-Barrier PEX | Non-Barrier PEX |
|---|---|---|
| Added layer | EVOH barrier (DIN 4726) | None |
| Blocks O₂ diffusion | ✓ Yes | ✗ No |
| Use for | Closed hydronic / radiant-floor heating | Potable (drinking) water |
| Protects | Boilers, pumps, steel/brass manifolds | — |
| Typical colors | Red / Blue / White | White / Blue / Red |
| Key standard | DIN 4726 + ASTM F876/F877 + EN ISO 15875 | ASTM F876/F877 + NSF/ANSI 61 |
| Certification focus | Heating spec | Potable safety (NSF-14, NSF/ANSI 61, cUPC, WRAS, DVGW) |
The rule is simple. Closed heating loop → oxygen-barrier PEX, every time — no barrier means oxygen corrosion. Potable water → non-barrier PEX — a barrier adds cost with no benefit on an open drinking-water line. Hitze supplies both from one house, so wholesalers and private-label brands cover heating and plumbing SKUs without splitting suppliers or paperwork.
FAQ
Oxygen-Barrier PEX FAQ — For Wholesalers, Contractors & Importers
Does your oxygen-barrier PEX meet DIN 4726?
Which sizes does oxygen-barrier PEX come in, and what’s the bend radius?
Why is an oxygen barrier needed for underfloor heating?
Can you private-label oxygen-barrier PEX and match my market’s certification?
What’s the difference between your barrier and non-barrier PEX?
Still deciding on barrier grade, size or certification? Request Oxygen-Barrier PEX Samples or Get Wholesale Pricing — we’ll match spec, market and manifold to your order.
Get Started
Request Oxygen-Barrier PEX Samples & a Quote
Send your 16/20/25 mm size mix, target market and volumes — we reply with pricing, MOQ, DIN 4726 data and the matching manifolds for a single-supplier hydronic loop.