Description of Flexible Plastic (PexFlex) Pipe System

In the Vital Energi PexFlex system, the service pipe is made of polyethylene (PEX) with an EVOH membrane that protects against oxygen diffusion. The system is used for distribution systems in community heating and district heating distribution systems, where there are lower temperature and pressure requirements.

An EVOH membrane located between the outer casing and the PUR insulation foam protects against any diffusion of oxygen and gases.

PexFlex pipes can be operated up to 95°C and have a maximum working pressure of 10 bar depending on size of service pipe.

PexFlex flexible pipe systems are available both as single and twin pipe solutions.

Vital Energi PexFlex pipes are fitted with a diffusion barrier to prevent diffusion of cell gases. Thus the insulating properties do not age over their entire service life.

Solution detail
Flexible PipeDimension mmTemp Range MaxLeak Detection SystemOperating PressureDiffusion BarrierSeries of Insulation ThicknessLambda Value W/mK
PexFlex16, 22 & 28

0°C to 85°C

No10 barYes10.022

20, 25, 32, 40, 50, 63, 7, 5, 90 & 110

0°C to 85°CNo6 barYes10.022

Applications for Flexible Plastic (PexFlex) Pre-Insulated Pipes

  • low-temperature
    Low Temperature Hot Water (LTHW)
  • condensate-water
    Domestic Hot & Cold Water

Key Benefits

  • Reduction in the number of joints needed through the availability of long lengths
  • Reduction in the number of bends/fittings needed as the flexibility allows the piping to follow the best and easiest path
  • Reduction of waste as pipe can be cut to measure
  • No special considerations necessary to take up thermal expansion
  • Reduction of excavation costs as pipes can be laid on top of each other and/or in very narrow trenches
  • No - dig methods (or boring) can be applied
  • Fully compliant with CIBSE CHPA Heat Networks Code of Practice
  • Request Flexible Plastic Pipe System document