Addressing district heating challenges with polymer

Polymer solutions in pre-insulated pipe address many of the challenges impacting the roll out of heat networks, but REHAU are taking this one step further, having listened extensively to industry feedback, from designers, installers and operators.

RAUVIPEX, polymer pre-insulated pipe, offers the optimum combination of thermal performance and reduced bending forces; developed from extensive industry feedback. This technically superior solution directly addresses the sector’s most pressing challenges, including thermal efficiency, facilitating faster installations, ensuring system longevity, and reducing lifecycle emissions.

A major factor in the roll out of heat networks is the skills shortage across the industry, polymer pre-insulated pipes offer an attractive alternative to traditional materials whilst also reducing the demand on skilled workforces. RAUVIPEX not only addresses this but also factors such as limited flexibility, added system security / reliability and thermal performance; where usually one or more of these would need to be compromised.

Whilst a polymer system is naturally more flexible than steel, there is however one complaint with PUR bonded foam systems - the high bending forces required for installing larger sizes. RAUVIPEX has addressed this with the newly designed, outer jacket featuring a crest-trough geometry and thick walls, enhancing impact resistance while reducing bending force, enabling greater flexibility and faster installation. In addition, the newly developed PUR foam, also offers impressive flexibility, whilst still maintaining high thermal performance. Overall, this gives 20-35% reduced bending forces compared with similar PU-foamed pipes, far more comparable to a non-bonded pipe system.

There has been no compromise on structural integrity, with the newly designed outer jacket having an SN8 rating, making it the first PU-foam pre-insulated pipe range to reach this milestone. This ring stiffness rating and extra layer of security from the longitudinal water barrier is not found in competitor systems, which instead rely solely on a thinner SN4 rated outer jacket for protection. This increased level of quality allows for a wider range of backfill options, with grain sizing up to 16mm, offering project savings, wider material choice and enabling more sustainable installation practices such as recycled glass backfill.

The fully welded longitudinal water barrier has been introduced to prevent moisture ingress into the insulation layer, even in the unlikely event of mechanical damage to the outer jacket, preserving thermal performance while extending system life. This extra level of protection has made RAUVIPEX the first flexible PU-foamed pipe to achieve AGFW 420-1 Class A standards, even when tested at double the standard test pressure.

All of these factors combined with REHAU’s tried and tested EVERLOC jointing system, which can be installed by mechanical contractors, create a system that is fit for the future and supports the roll out of low carbon heat networks.

RAUVIPEX proven in practice

Sizing is also no longer a barrier with the PP-R pipe offering a large diameter polymer solutions for heat networks. Being up to 36% lighter than steel, this offers saving in transportation and facilitates easier handling.

Case study

These innovations combined with extensive global experience in polymer district heating networks, offer our customers an expert partner in low carbon projects - taking heat networks to the next level. From new-build housing, commercial sites, retrofitting and more our team are on hand to support every step of the way.