Flexible pre-insulated reinforced plastic pipes for heating applications

Tubo preisolato flessibile rinforzato FibreFlex

Technical Properties

  Peak temperature +95 °C
  Seasonal op temp +85 °C
  PUR thermal cond 0.021 W/mK
  Operating Pmax 10 bar
  Configuration single or duo pipe

FibreFlex is the new generation of flexible pre-insulated bonded pipes for low temperatures district heating applications with plastic reinforced core pipes able to perform up to 95° peak temperature and 10 bar pressure.

FibreFlex service pipes have a multilayer pipe wall construction, comprising a cross-linked polyethylene PEX-a inner layer, a high modulus aramid fibre mesh reinforcement layer, an oxygen barrier and additional high temperature resistant thermoplastic adhesive layers used to bond the individual layers to form the composite pipe structure.

FibreFlex pipes are continuously insulated during the manufacturing process using a CFC free bonded polyurethane foam with an outstanding thermal conductivity value of 0.021 W/mK. The product range finally includes two insulation classes with different wall thickness of polyurethane foam in order to comply to any insulation requirement due to different outside temperature conditions.

FibreFlex is the best solution for:

  • Revamping of residential heating systems with underground hot water distribution networks
  • Small low temperature district heating networks
  • Agricultural applications (biogas plants, biomethane plants, biomass plants, etc.)
  • High pressure district heating networks in hilly areas

Key Benefits

  • FibreFlex Pro pipe systems are first of all flexible, so all the designing and installation issues are very simple. Especially the installation benefits merge wherever the FibreFlex Pro should be installed close to already existing pipelines or in very hard trench conditions between trees and buildings.
  • Fibreflex Pro pipes can be used without any need of complex thermal expansion calculations: actually there is no need of thermal expansion compensators and this means fast and simple design.
  • Preinsulated pipes systems FibreFlex Pro are generally supplied in long length coils or, wherever it is required for the pipeline extension, coiled on drums too. The pipes are usually supplied on lengths required by customers, dramatically reducing the quantity of joints.
  • The FibreFlex Pro press jointing system overcomes the need to employ qualified on-site welding techniques normally associated with rigid district heating systems. Due to the extremely low number of joints, the time required to restore the insulation is thus completely negligible compared to the traditional systems mentioned above.

These longer continuous flexible pipe lengths, combined with an easy to install non-welded fittings solution, enables FibreFlex Pro pipes to be installed in long runs using narrow trenching techniques, offering significant on-site installation time and cost savings.

Product Range

Service Pipe
D x s [mm]
Casing Pipe
OD [mm]
32/91 32.0 x 2.9 91 570
40/111 40.0 x 3.7 111 410
50/111 49.4 x 3.6 111 410
63/126 58.5 x 4.0 126 300
75/142 69.5 x 4.6 142 220 (440*)
90/162 84.0 x 6.0 162 150 (300*)
110/182 101.0 x 6.5 182 86 (170*)
125/202 116.0 x 6.8 202 80 (160*)
140/202 127.0 x 7.1 202 80 (160*)
160/225 144.0 x 7.5 225 75 (150*)

* Maxicoil available on request (width 2.4 m)

Product Range DUO

Service Pipe
D x s [mm]
Casing Pipe
OD [mm]
25+25/111 25.0 x 2.2 111 410
32+32/126 32.0 x 2.5 126 300
40+40/142 40.0 x 2.8 142 220 (440*)
50+50/162 49.4 x 3.6 162 150 (300*)
63+63/182 58.5 x 4.0 126 86 (170*)
75+75/202 69.5 x 4.6 142 80 (160*)
90+90/225 84.0 x 6.0 162 80 (160*)

* Maxicoil available on request (width 2.4 m)

Jointing and Insulation of Joints

Raccordi in acciaio FibreFlex e FibreFlex ProThe jointing of flexyble preinsulated reinforced pipes FibreFlex Pro is made by mechanical axial compression couplers to be installed by means of hydraulic clamps.

Those joints are made of 3 pieces:
– Internal steel male insert
– Polymer sleeve for high temperatures
– External steel ring

FibreFlex Pro is quick and easy to join using the abovementioned specially designed compression fittings, incorporating a unique polymer sleeve, which is inserted between the fitting’s outer sleeve and the service pipe. The steel insert is then easily fitted inside the pipe without any need for the pipe end to be expanded before the connection. This provides a robust and very secure joint.

The insulation of the joint is finally made with high density polyethylene or even better crosslinked polythylene shrinkable muffs as for the traditional steel preinsulated pipes.

Pre-insulated Fittings

Preinsulated fittings for FibreFlex and FibreFlex Pro flexible pipe systemsFlexyble preinsulated reinforced pipes FibreFlex Pro have their own full range of steel preinsulated fittings with already welded steel male adaptor in order to avoid any further welding on worksite for a safer and faster installation.

Branch TEE pieces can be manufactured with different outlets:
– 45°, plain or parallel
– equal or reduced

To conclude, wherever it is not possible to bend the flexy pipes at required radius a complete range of preinsulated bends with both steel or plastic service pipe is available.

Reference Standards

ZG 200-2 Flexible pre-insulated pipe systems for district heating networks with bonded thermoplastic reinforced service pipe
EN 15632-2 District heating pipes – Pre-insulated flexible pipe systems – Part 2: Bonded plastic service pipes – Requirements and test methods

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