Gerpex MultiLayer Composite Pipe

Gerpex Multi-Layer Composite Pipe is the optimum solution for modern building projects, offering all of the advantages of both plastic and metal pipes combined with excellent value for money and peace of mind. Gerpex can be used in a wide range of applications including sanitary systems and heating (wall hung radiator and underfloor heating), chilled water and compressed air. The pipe is available in a range of sizes from 14-63mm making it ideal for both domestic and commercial buildings.

gerpex sizing

Gerpex Multi-Layer Composite Pipe is made of composite material through a technologically advanced process in which an inner layer of cross linked PE-Xb (polyethylene) pipe is bonded to a butt-welded aluminium core with outer layer of PE-Xb (up to 32mm) or PE-HD (from 40 up to 63mm). The composition is what gives Gerpex its high temperature and pressure characteristics. The internal aluminium layer provides rigidity, form retention, and a solid oxygen barrier to prolong the life of heating system components such as heat exchangers, pumps and radiators.

The products are fully WRAS approved for use with sanitary systems and the range includes coils up to 500m, 4m straight bars and insulated coils.

Technical Data

Key Product Features

  • High resistance to pressure – Resistant to pressures up to a maximum of 10 bar (at 95 °C).
  • Reduced linear expansion – The linear expansion in relation to a variation in temperature is comparable with that of copper.
  • Thermal insulation – The system is available with an insulating coating which meets the following fire safety standards: European Standard Class 1 (UNI 9177) – DLs2-d2 (EN 13501-1).
  • Low internal resistance- The smooth interior surface of the pipe prevents limescale deposits and promotes the smooth flow of fluid thus considerably reducing pressure drops across the system.
  • High resistance to temperatures – Resistance to temperatures up to a maximum of 95 °C.
  • Resistance to damage and abrasion – This is due to the resistance of the aluminium layer and of the layers in PE-X used in the pipe’s construction.
  • Solid oxygen barrier – The aluminium layer makes the Gerpex pipe impermeable to oxygen that would cause corrosion of the system’s metallic components (e.g. inside a boiler) by providing a solid barrier.
  • Resistance to external chemical agents – Gerpex pipes embedded in walls or buried under flooring can be, due to their qualities, placed in “acidic” and “alkali” environments.
  • Complete resistance to electrochemical corrosion – The materials used in the pipe’s construction and the adoption in the fittings of a special dielectric element mean that the fittings are fully resistant to electromechanical corrosion.



Emmeti Hot and Cold Plumbing Manifolds Sales Brochure

Product and system guide with selector tables, range information and case studies for Hot and Cold Manifold applications

Emmeti Wall Hung Radiator Manifolds Sales Brochure

Product and system guide with selector tables, range information and examples for wall hung radiator manifold applications


Gerpex Technical Brochure 2021

Gerpex Installation Guide

GERPEX MultiLayer Composite Pipe & Press Fit System Installation Guide


I can see that TH profiles are WRAS approved with Gerpex Press Fittings. Can I use other jaw profiles?
Gerpex Press Fittings are WRAS approved when use in conjunction with TH profile pressing jaws. However the fittings are fully compatible with B profile up to 32mm and U, H & F up to 20mm sizes. B, U, H & F profiles don’t have the WRAS approval with Gerpex Press Fittings so please check potable water requirements for the project with the architect, project manager, etc as appropriate before using these jaw profiles.

Does Gerpex Multi-layer Composite Pipe need metal tracer tapes as per the NHBC requirements for metal detection?
No, the aluminium core within the Gerpex pipe can be picked up with a metal pipe detector.

I see that Gerpex Multi-layer Composite Pipe has a butt welded aluminium core, is this better than products with lapped joints?
The butt welded aluminium core ensures a consistent pipe diameter and a more circular pipe cross section allowing water to travel with less resistance providing a benefit.

Can I connect Gerpex Multi-layer Composite Pipe directly to a boiler?
Most boiler manufactures require a minimum length of a metal pipe before allowing connection to MLCP. Please check with the boiler manufacturer’s instructions before considering any connections directly to the boiler. At Emmeti we have developed MLCP to copper fittings for ease of connection.

Can I use Gerpex Multi-layer Composite Pipe for underfloor heating loops?
Yes it’s perfectly possible to use 16mm Gerpex for example in UFH applications. However, at Emmeti we also offer two other pipe products specifically for UFH (Alpert MLCP and PE-Xa barrier pipe). Both of these products may provide a more cost effective solution for this particular application.

Can underfloor heating pipe be used for radiator central heating?
Emmeti’s range of PE-Xa and PE-Xc is suitable to be used in general heating applications, with maximum operating temperatures of 95oC and 90oC respectively. Our Gerpex range is the most suitable for high temperature radiator applications due to its maximum operating temperature of 95oC

What is the difference between PE-RT/AL/PE-RT (Alpert) and Gerpex MLCP?
Both Alpert and Gerpex are Multilayer Composite Pipes, Alpert is made up of layers of PE-RT and Aluminium whereas Gerpex is made up of layers of PE-Xb (and PE-HD for sizes over 40mm) and Aluminium. Alpert is designed for UFH and low temperature heating applications due to its maximum operating temperature of 70oC. Gerpex is designed for a wide range of sanitary and heating applications. It’s maximum operating temperature is 95oC.