INSULPEX pre-insulated PEXa piping

Flexible energy transfer pipe for underground installations

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

Increase flexibility
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.

Minimize 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.

Streamline 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.

Enhance 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. 

REHAU Academy On-air | Pre-insulated PEXa piping with Kevin Hale

In this free, pre-recorded online webinar REHAU account manager Kevin Hale outlines ideal applications for pre-insulated PEXa piping, with a focus on project profiles.  See how creative design/build firms are leveraging this technology, as an alternative to steel.

Watch here

Technical downloads

Check our database of up-to-date technical bulletins, specifications, submittals, product instructions and more.


Product catalog

REHAU Building Solutions product catalog in a downloadable PDF file.                                                                                                                      


Find a distributor

Ready to buy? REHAU products are sold exclusively through local, regional and national authorized distributors.

Find a distributor

Engineering progress

Enhancing lives

Maximum cart size of 3 items has been reached!

Your sample cart items: