PEX TYPE PIPE
Legom PEX Type Pipe is a cross-linked polyethylene pipe engineered for underfloor heating and hydronic HVAC systems. The cross-linking process restructures the molecular bonds of the polyethylene material, producing a pipe that performs significantly better than standard PE pipe in terms of heat resistance, pressure durability, and long-term dimensional stability. With a cross-linking degree above 65% and a Vicat softening temperature of 124°C, this pipe is built to handle the continuous thermal cycling demands of modern radiant heating systems.
Free from plasticizers and engineered to resist microbial growth, Legom PEX pipe is a reliable choice for both residential and commercial floor heating installations where hygiene, durability, and installation flexibility are priorities. The pipe carries an oxygen permeability rating of ≤0.32 mg/m²d per DIN 4726, protecting system components from oxygen-induced corrosion over the long term.
Key Benefits
- High cross-linking degree – Cross-linking above 65% per DIN 16892 delivers superior heat resistance, creep strength, and long-term pressure integrity compared to non-crosslinked polyethylene
- Oxygen barrier protection – Oxygen permeability of ≤0.32 mg/m²d per DIN 4726 prevents oxygen ingress into the heating circuit, protecting metal components from corrosion
- Chemical-free composition – Free from plasticizers, ensuring the pipe does not leach harmful substances into the water circuit over time
- Anti-microbial properties – Engineered to resist mildew and bacteria growth, promoting a cleaner and more hygienic water system
- High Vicat softening temperature – Rated at 124°C per ISO 2507, the pipe maintains its shape and structural integrity at operating temperatures well above standard floor heating range
- No-fracture impact strength – Passes ISO 179 impact testing at 23°C with no fracture, confirming toughness during installation and in service
- Flexible and easy to install – Unlike rigid pipe materials, PEX can be bent to follow floor heating loop patterns without becoming brittle or requiring additional fittings at curves
- Corrosion and scale resistant – Smooth inner bore resists scale buildup and is immune to the electrochemical corrosion that affects copper and steel pipes
- OEM and ODM customization available – Pipe diameter, coil length, wall thickness, and labeling can be customized for distributor and system integrator requirements
Technical Specifications
| Product Parameter | Unit | Standard Value | Standard |
|---|---|---|---|
| Density | g/cm³ | 0.949 | ISO 1183 |
| Tensile yield stress | MPa | 27 | ISO 527 |
| Tensile yield elongation | % | 500 | ISO 527 |
| Elastic modulus | MPa | 950 | ISO 527 |
| Impact strength [23°C] | KJ/m² | No fracture | ISO 179 |
| Thermal expansion coefficient | m/m°K | 0.13E-4 | DIN 53752 |
| Thermal conductivity [60°C] | W/m°K | 0.43 | DIN 52612 |
| Vicat softening temperature | °C | 124 | ISO 2507 |
| Oxygen permeability | mg/m²d | ≤ 0.32 | DIN 4726 |
| Cross-linking degree | % | > 65 | DIN 16892 |
Application & Use Cases
- Underfloor heating systems – The primary application for PEX pipe. Flexible enough to follow serpentine and spiral loop patterns embedded in screed or fitted to aluminum diffuser plates in dry systems
- Radiant ceiling and wall heating – Used in radiant panel systems where the pipe is routed through ceiling or wall cavities, taking advantage of PEX flexibility to navigate structural constraints
- Hydronic HVAC distribution – Suitable for low-temperature hot water distribution in heating systems connected to heat pumps, condensing boilers, or district heating networks
- Domestic hot water systems – The plasticizer-free, anti-microbial composition makes it appropriate for potable water distribution in residential and light commercial buildings
- Chilled water circuits – Used in radiant cooling systems where chilled water is circulated through floor or ceiling panels for summer cooling
- Renovation and retrofit projects – The flexibility of PEX allows pipe to be routed through existing wall cavities and floor structures where rigid pipe cannot be installed without major structural work
Installation Notes
- Store pipe coils in a cool, shaded location away from direct sunlight and heat sources before installation to prevent premature deformation
- Maintain the minimum bend radius specified for the pipe diameter during installation. Forcing the pipe below minimum bend radius can cause kinking that permanently restricts flow
- Use pipe staples, clips, or rail systems at recommended spacing intervals to hold the pipe in position before screed or concrete is poured in wet system installations
- In dry system installations with aluminum diffuser plates, ensure the pipe seats fully into the plate channel to maximize thermal contact and heat transfer efficiency
- Allow adequate expansion clearance at pipe entry and exit points through walls and floor edges, as PEX expands and contracts with temperature changes during system operation
- Protect pipe penetrations through concrete or screed with conduit sleeves to prevent abrasion and allow for thermal movement
- Use only compatible PEX fittings (press, crimp, or expansion type depending on the PEX variant) at all connection points. Do not use fittings designed for PE-RT or other pipe types
- Conduct a pressure test before screed or concrete is poured. Test at a minimum of 1.5 times the intended working pressure and hold for at least 30 minutes
- Do not exceed the pipe’s maximum operating temperature. For continuous use, consult the system design pressure-temperature rating curve for the specific pipe diameter and wall thickness
- Label each loop at the manifold connection point during installation to simplify commissioning and future maintenance
Frequently Asked Questions
What does the cross-linking degree mean and why does it matter?
Cross-linking is a manufacturing process that creates additional molecular bonds between the polyethylene polymer chains. A higher cross-linking degree results in better resistance to heat, pressure creep, and chemical attack compared to standard polyethylene. Legom PEX pipe achieves a cross-linking degree above 65% per DIN 16892, placing it in the performance range required for reliable long-term use in pressurized heating systems.
Why is the oxygen barrier important in a floor heating pipe?
Oxygen that permeates into the heating water circuit causes oxidation of ferrous metal components including pumps, boiler heat exchangers, and manifold valves. Over time this produces sludge and accelerates corrosion-related failures. Legom PEX pipe’s oxygen permeability of ≤0.32 mg/m²d per DIN 4726 limits oxygen ingress to a level that protects system components and extends their service life.
How does PEX pipe compare to PE-RT pipe for underfloor heating?
Both PEX and PE-RT are widely used for underfloor heating. PEX achieves its enhanced properties through cross-linking after extrusion, while PE-RT achieves heat resistance through controlled crystalline structure during manufacturing. PEX generally offers higher resistance to stress cracking and slightly better long-term creep performance, while PE-RT allows for standard heat-fusion jointing methods. The choice depends on system design requirements and the preferred installation method. Legom supplies both pipe types to suit different project specifications. See also: PE-RT 5-Layer Oxygen Barrier Pipe and PE-RTII Type Pipe.
Is Legom PEX pipe safe for use in drinking water systems?
Yes. The pipe is free from plasticizers, which are chemical additives found in some flexible plastic materials that can migrate into the water supply. Combined with its anti-microbial properties that resist mildew and bacteria growth, Legom PEX pipe is suitable for potable water applications.
What sizes and coil lengths are available?
Please contact the Legom team for current availability of pipe diameters, wall thicknesses, and coil lengths. OEM and ODM orders can be fulfilled with custom specifications including diameter, wall thickness, coil length, and print labeling.
Can Legom PEX pipe be customized for private label or OEM supply?
Yes. Legom supports full OEM and ODM services for PEX pipe including custom dimensions, coil lengths, color, and branded printing on the pipe surface. All customization projects are handled under strict confidentiality. Contact our team to discuss your requirements.
OEM & ODM Customization
Legom supports full OEM and ODM services for PEX Type Pipe. Our manufacturing team can customize pipe diameter, wall thickness, coil length, surface printing, and packaging to match your product and brand requirements. All customization projects are handled with strict confidentiality. Contact us via WhatsApp or info@legomsmart.com.
Product information last reviewed by the Legom Technical Team. For the most current specifications, refer to the official datasheet or contact our sales team.
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Legom is a direct manufacturer offering end-to-end OEM and ODM services. With our in-house engineering and production capabilities, we work closely with distributors and system integrators to deliver fully customized solutions under strict NDA.
