Flexible energy transfer pipe for underground installations

INSULPEX pre-insulated PEXa piping

INSULPEX® is specially designed for the efficient transfer of hot or chilled water through buried pipelines. INSULPEX consists of PEXa O2 Barrier pipe surrounded by a solid layer of CFC-free polyurethane foam insulation and an LDPE outer jacket. 

INSULPEX is available in one- and two-pipe configurations. The two-pipe configuration combines supply and return pipes, for even faster installations.

INSULPEX single pipe dual pipe

Key benefits

As an alternative to rigid piping systems, the flexibility of INSULPEX allows it to easily bend around obstacles, or be directionally bored, offering ease of installation while reducing  labor costs.

Minimal energy loss
INSULPEX pipe is specially designed for the efficient transfer of heated or chilled water through buried pipelines, offering a continuous piping system that minimizes temperature change. This equates to increased efficiency in the mechanical room and cost savings to the owner.

Streamlined installation
Accessories such as anchors, kickers and thrust blocks that are required on rigid systems are not required when installing INSULPEX. This is made possible by the self-compensating properties of the ribbed pipe and the dependability of fittings.

Long-term performance
Crosslinked O2 barrier PEXa pipe offers long-term strength. The high degree of crosslinking in REHAU crosslinked polyethylene (PEXa) pipe provides durability and flexibility with enhanced temperature and pressure capabilities.

How it works

Remote boiler plants or energy centers, often using renewable energy sources such as geothermal, biomass or combined heat and power, are increasingly employed in multi-building projects. These facilities offer efficient heating and cooling solutions, but are usually located outside of the buildings where the energy is needed. As a result, ensuring minimal temperature change between the energy center and the buildings is an important design consideration. REHAU pre-insulated PEXa piping is specially designed for the efficient transfer of hot or chilled fluid through buried pipelines. Great applications for INSULPEX:

  • District heating
  • Chilled water distribution
  • Process piping
  • Hydronic piping
  • Geoexchange systems
  • Outdoor wood boilers


INSULPEX bend radius

Your trench doesn't need to be laser straight, the flexibility of INSULPEX lets you easily navigate around slight bends.  Carefully unroll the coil into the trench and move on. 

INSULPEX uncoiling

Two-pipe configurations save additional installation time.  In some cases, you can use a single, continuous coil to cover over 900 feet.

INSULPEX pressure test

Connections are made with SDR11 compression-sleeve fittings.  No welding or power required in the trenches and you can pressure test immediately. 

Contact a REHAU expert to talk about an INSULPEX project

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