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A pre-insulated PE-Xa pipe system for heat networks

A highly-efficient, flexible pre-insulated PE-Xa pipe system, HeatFlex is perfect for district heating networks that operate at temperatures up to 95°C and pressures of 6 bar.

The system’s composite construction comprises of a cross-linked polyethylene (PE-Xa) service pipe encased in a bonded layer of closed-cell PUR foam insulation which is protected by a tough, yet flexible, corrugated LDPE outer casing. Easy to install, with a full range of components and fittings available, the system is supplied in coils of up to 800m in length which minimises the requirement for on-site joints. This helps lower installation costs and the system’s outstanding thermal performance also benefits operational expenditure. The system is available with single and twin service pipe configurations within a single outer casing.


Buried district heating networks

Diameter Range 25 mm to 140 mm (OD) (service pipe) Bespoke: No
SDR 11 Bespoke: No
Max Operating Pressure 6 bar
Lengths Up to 800 m coils Bespoke: Yes
Compliance / Approvals Pipe system: EN 15632-1/2, EN ISO 15875-2.5, DIN 16892 and DIN 16893
Approved Fittings & Jointing Techniques

Axial compression service pipe joints


New installations
System extensions
System replacements

Jointing Techniques

Axial compression service pipe joints
Mechanical joint on outer casing
Optional heat-shrink casing joint

Jointing Equipment Axial compression tooling with hydraulic pump (manual or electrically operated), hand tools for service pipe preparation and gas burner for optional heat-shrink casing joint
Installation Techniques


Maximum Temperature (peak):


Thermal Conductivity:

≤0.021 W/mK at 50°C

Service pipe configuration:

Single and Twin

Pipe system material:

Cross-linked polyethylene (PE-Xa) service pipe with EVOH diffusion barrier, PUR insulation and LDPE outer casing

Pipe system colour:

Red (service pipe), Black with longitudinal green stripes (outer casing)