PEX-AL-PEX pipe 26 x 3 for heating, underfloor heating and water

Product detailed description

Five-layer PEX-AL-PEX composite pipe 26 x 3.0 mm for hot and cold water distribution, heating and underfloor heating.

The pipe consists of an inner and outer layer of cross-linked polyethylene (PEX) with a layer of aluminium foil inserted between them (thickness 0.30 mm) - this combination unites the advantages of both metal and plastic pipes. The aluminium layer ensures that the pipe holds its shape after bending and does not spring back (unlike pure PEX), while also significantly limiting its linear expansion under temperature changes (coefficient of only 0.026 mm/m.K). Thanks to the aluminium layer acting as an oxygen barrier, oxygen is also prevented from entering the heating water, which would otherwise cause corrosion of the system's metal parts (boiler, radiators, pump).

What makes this pipe stand out

• Smooth inner surface made of cross-linked polyethylene (0.007 mm/m roughness) means low pressure loss during flow and resistance to limescale build-up.
• Shape stability thanks to the aluminium layer - the pipe stays in shape after bending, making it easier to route around obstacles without needing additional fittings.
• Long service life - the material is corrosion-resistant and, provided the operating parameters (pressure, temperature) are observed, the declared service life is on the order of decades.
• Low thermal conductivity of the pipe wall (0.45 W/m.K) limits heat loss directly through the pipe wall when distributing heating water.

Technical parameters

• Dimension (outer diameter x wall thickness): 26 x 3,0 mm
• Inner diameter: 19,9 mm
• Water volume: 0,201 l/m
• Pipe composition: PEX/AL/PEX composite
• Max. operating pressure: 10 bar
• Max. operating temperature: 95 °C short-term, 70 °C continuous operation
• Material class: B2 per DIN 4102
• Colour: white
• Standard: DIN EN ISO 21003
• Country of origin: EU
• Bend radius without tool: min. 5 x outer diameter (in mm)
• Bend radius with bending spring: 3 x outer diameter (in mm)
• Recommended fittings: Compression (screw) fittings

Packaging and ordering

The minimum order is 10 metres, and further quantities are added in multiples of 10 metres. The pipe is supplied in complete packages (coils) and, for larger orders, we do not cut it into parts smaller than one package.

Frequently asked questions

• Is this 26 x 3.0 mm pipe also suitable for underfloor heating? This larger size is used more for main distribution lines and connecting the manifold to the heat source, where higher flow is needed - smaller diameters (16 or 20 mm) are more commonly used for the underfloor heating circuits themselves.
• What is the difference between PEX and PEX-AL-PEX pipe? Pure PEX pipe is made only of cross-linked polyethylene without an inserted layer, while PEX-AL-PEX additionally has an aluminium layer that provides shape stability and reduces linear expansion under temperature changes.
• Which fittings are used to join this pipe? Compression (screw) fittings in a size exactly matching 26 x 3.0 mm are used - do not combine fittings from different systems.
• What is the smallest bend radius the pipe can withstand? Without a tool, min. 5 x outer diameter (in mm); with a bending spring, the pipe can be bent more tightly, to 3 x outer diameter (in mm).
• Must the installation be carried out by a professional? Routing and laying the pipe itself can be handled by an experienced DIY enthusiast if the instructions are followed, but we recommend having the connection to the heat source (boiler) and system commissioning checked by a heating technician.