PEX/AL/PEX Multilayer Composite Pipe (MLCP)

PEX/AL/PEX Multilayer Composite Pipe

PEX/AL/PEX Multilayer Composite Pipe combines the flexibility of PEX with the strength and stability of an aluminium layer. As a result, it provides a versatile pipe solution for modern plumbing, heating and water underfloor heating installations.

The multilayer construction consists of an inner PEX layer, an aluminium core and an outer PEX layer. Furthermore, adhesive layers bond the materials together to create a strong composite structure.

Importantly, the aluminium layer provides an effective oxygen barrier. It also helps the pipe retain its shape after bending. Therefore, installers gain the benefits of flexible plastic pipe with greater dimensional stability.

PEX/AL/PEX pipe suits a wide range of domestic and commercial applications. For example, installers can use compatible sizes for hot and cold water distribution, radiator heating and wet underfloor heating systems.

Why Choose PEX/AL/PEX Multilayer Pipe?

Strong Multilayer Construction

PEX/AL/PEX combines polymer and aluminium layers within one pipe. Consequently, the finished pipe offers excellent strength while remaining flexible enough for efficient installation.

Aluminium Oxygen Barrier

The central aluminium layer acts as an oxygen barrier. Therefore, it helps prevent oxygen from passing through the pipe wall into a closed heating system.

Excellent Shape Retention

Standard flexible plastic pipe can naturally try to return towards its original coil shape. However, the aluminium layer within PEX/AL/PEX helps the pipe retain bends after forming.

Low Thermal Expansion

The aluminium layer also reduces thermal expansion compared with many all-plastic pipes. As a result, PEX/AL/PEX provides greater dimensional stability as system temperatures change.

Flexible and Easy to Install

PEX/AL/PEX can follow changes in direction without requiring a fitting at every bend. Consequently, installers can reduce the number of connections required across suitable installations.

Suitable for Multiple Applications

Depending on the pipe size and system specification, PEX/AL/PEX can suit plumbing, radiator heating and water underfloor heating. Therefore, it provides a versatile option for many modern installations.

Key Features

• Multilayer composite pipe construction
• Inner PEX layer
• Aluminium core
• Outer PEX protective layer
• Integrated oxygen barrier
• Strong and durable construction
• Excellent dimensional stability
• Good shape retention
• Flexible installation
• Reduced thermal expansion
• Smooth internal bore
• Corrosion-resistant pipe construction
• Suitable for compatible hot and cold water systems
• Suitable for central heating applications
• Ideal for water underfloor heating
• Suitable for domestic and commercial installations
• Compatible with appropriate multilayer pipe fittings

PEX/AL/PEX Pipe Construction

PEX/AL/PEX uses several layers to combine the advantages of plastic and metal pipe technology.

The typical construction includes:

• Inner PEX Layer – provides a smooth internal waterway
• Adhesive Layer – bonds the inner PEX to the aluminium
• Aluminium Layer – provides strength, stability and an oxygen barrier
• Adhesive Layer – bonds the aluminium to the outer layer
• Outer PEX Layer – protects the aluminium and completes the composite structure

Together, these layers create a pipe that remains flexible while offering excellent stability.

What Is PEX/AL/PEX Pipe?

PEX/AL/PEX is a multilayer composite pipe that combines cross-linked polyethylene with aluminium.

The letters describe its construction:

PEX / Aluminium / PEX

The inner and outer polymer layers provide flexibility and protection. Meanwhile, the aluminium core adds strength and dimensional stability.

Consequently, PEX/AL/PEX bridges the gap between traditional metal pipe and flexible plastic pipe. Installers gain a pipe that bends easily while retaining many of the handling characteristics associated with rigid pipework.

Aluminium Oxygen Barrier

Oxygen ingress can create problems within closed heating systems. For example, dissolved oxygen can contribute to corrosion of susceptible metallic system components.

The aluminium layer within PEX/AL/PEX Multilayer Composite Pipe creates an effective barrier against oxygen diffusion.

Therefore, PEX/AL/PEX makes an excellent choice for closed-loop heating applications. These include radiator circuits and water underfloor heating systems.

Furthermore, the aluminium layer forms part of the pipe itself. As a result, the oxygen barrier remains protected between the inner and outer polymer layers.

PEX/AL/PEX Pipe for Underfloor Heating

PEX/AL/PEX works particularly well in water underfloor heating systems.

Its flexibility allows installers to create smooth heating loops across the floor. Meanwhile, its shape retention helps keep the pipe in position during installation.

Furthermore, the oxygen barrier makes the pipe suitable for closed heating circuits. The smooth internal bore also supports efficient water circulation through each underfloor heating loop.

A typical system connects individual pipe circuits to an underfloor heating manifold. The manifold then distributes heated water across each heating zone.

PEX/AL/PEX pipe can work with:

• Underfloor heating manifolds
• Manifold Eurocones
• Pipe clips
• Clip rail
• Castellated panels
• Overlay systems
• Mixing valves
• Pump sets
• Thermal actuators
• Underfloor heating controls

PEX/AL/PEX Pipe for Plumbing

Suitable PEX/AL/PEX pipe also provides a practical solution for modern plumbing installations.

Its flexible construction allows installers to route pipe through floors, walls and service spaces. Therefore, fewer fittings may be required compared with traditional rigid pipework.

Furthermore, the aluminium layer helps the pipe maintain its shape. This makes neat pipe runs easier to achieve.

Depending on the pipe specification and approvals, applications can include:

• Hot water distribution
• Cold water distribution
• Plumbing manifolds
• Bathroom supplies
• Kitchen supplies
• Utility rooms
• Distribution pipework
• Domestic plumbing
• Commercial plumbing

Always confirm that the specific pipe and fittings carry the required approvals for the intended application.

Ideal for Plumbing Manifold Systems

PEX/AL/PEX works particularly well with plumbing manifold systems.

A central manifold can distribute hot or cold water through individual pipe runs to each outlet. Consequently, installers can create an organised plumbing system with fewer concealed joints.

Individual pipe runs can supply:

• Basins
• Baths
• Showers
• Toilets
• Kitchen sinks
• Appliances
• Utility rooms
• Other suitable outlets

Compatible Eurocone or manifold connectors provide the connection between the multilayer pipe and manifold.

PEX/AL/PEX for Central Heating

PEX/AL/PEX also suits compatible central heating installations.

The pipe can carry heating water between system components while its aluminium barrier helps limit oxygen diffusion.

Furthermore, its lower expansion and excellent shape retention make installation straightforward. As a result, multilayer pipe provides a useful alternative to traditional copper or standard plastic heating pipe.

Suitable applications can include:

• Radiator circuits
• Heating distribution
• Boiler-fed heating systems
• Heat pump systems
• Zoned heating systems
• Underfloor heating
• Low-temperature heating systems

Always size the pipe correctly for the required flow rate, pressure and heat load.

Excellent Shape Retention

One major advantage of PEX/AL/PEX pipe is its ability to retain its shape.

The aluminium core helps the pipe remain in position after bending. Therefore, installers can form smooth bends without the pipe continually trying to return to its original coil.

This characteristic can make installation particularly convenient around corners and through complex pipe routes.

Furthermore, fewer direction-change fittings may be necessary. Consequently, installers can create long continuous pipe runs with fewer mechanical connections.

Reduced Thermal Expansion

Pipework expands and contracts as its temperature changes.

However, the aluminium layer within PEX/AL/PEX helps control this movement. Therefore, multilayer composite pipe generally offers lower thermal expansion than conventional all-plastic pipe.

This additional stability can help create neater pipe runs. Furthermore, it can reduce unwanted movement as heating systems warm up and cool down.

Smooth Internal Bore

The inner PEX layer creates a smooth waterway through the pipe.

Consequently, water can flow efficiently through correctly sized pipework. The smooth internal surface also avoids the internal corrosion associated with some traditional metallic materials.

This makes PEX/AL/PEX particularly suitable for long-term plumbing and heating installations.

Easy Pipe Routing

Flexible pipe can significantly reduce installation time.

PEX/AL/PEX can bend around suitable corners and obstacles. Therefore, installers do not need an elbow fitting for every change in direction.

Fewer fittings can provide several benefits:

• Faster installation
• Fewer connections
• Cleaner pipe routes
• Reduced fitting requirements
• Less installation complexity

However, installers must always observe the specified minimum bend radius.

How to Install PEX/AL/PEX Pipe

Correct pipe preparation plays an important role in creating a reliable connection.

Firstly, cut the pipe squarely using a suitable multilayer pipe cutter.

Next, use the correct reaming and calibration tool. This restores the pipe end to the correct shape and prepares it for the fitting.

Then, insert the appropriate fitting according to the manufacturer’s instructions.

Finally, complete the connection using the correct fitting system and installation tools.

Always use fittings specifically designed for the pipe size and wall thickness.

Why Is Reaming PEX/AL/PEX Important?

Cutting multilayer pipe can slightly distort its circular profile. Therefore, installers should correctly prepare the pipe end before inserting a fitting.

A suitable reamer or calibrator restores the correct internal shape. Furthermore, many tools also chamfer the inside edge.

This preparation helps the fitting enter correctly without damaging its seals.

Consequently, a multilayer pipe reamer should form part of the installation toolkit when fitting PEX/AL/PEX pipe.

Choosing the Correct PEX/AL/PEX Fittings

Always match the fitting to the exact pipe dimensions.

For example, a fitting designed for one wall thickness may not suit another pipe with the same outside diameter.

Check:

• Outside pipe diameter
• Pipe wall thickness
• Fitting type
• Manufacturer compatibility
• System pressure
• Operating temperature
• Application requirements

Using correctly matched components helps create a reliable installation.

PEX/AL/PEX vs Standard Plastic Pipe

Both pipe types can provide excellent performance when correctly specified.

However, PEX/AL/PEX contains an aluminium layer. Consequently, it offers greater shape retention and reduced thermal expansion.

Standard plastic pipe can provide excellent flexibility. In contrast, multilayer pipe combines flexibility with additional rigidity.

Therefore, PEX/AL/PEX can provide an excellent option when installers want flexible installation with improved dimensional stability.

PEX/AL/PEX vs Copper Pipe

Copper remains a popular plumbing and heating material. However, multilayer composite pipe offers several installation advantages.

PEX/AL/PEX bends around suitable changes in direction. Therefore, fewer elbow fittings may be required.

Furthermore, the pipe does not suffer from external corrosion in the same way as exposed metallic pipework.

The lightweight coil format also makes transportation and handling straightforward.

Both materials have appropriate applications. Therefore, the correct choice depends on the system design and installation requirements.

Ideal Applications

PEX/AL/PEX Multilayer Composite Pipe suits:

• Water underfloor heating
• Radiator heating
• Central heating systems
• Heat pump installations
• Boiler heating systems
• Plumbing manifolds
• Hot water distribution where approved
• Cold water distribution where approved
• Domestic plumbing
• Commercial plumbing
• New build properties
• Renovations
• Extensions
• Zoned heating systems
• Low-temperature heating systems

Related Products

Plumbing Manifolds

Create organised hot and cold water distribution systems with individual pipe runs to each outlet.

Plumbing Manifold Ball Valves

Add isolation to compatible plumbing manifolds for easier installation and future maintenance.

PEX/AL/PEX Eurocones

Connect compatible multilayer pipe securely to manifolds using the correct size Eurocone.

Underfloor Heating Manifolds

Distribute heating water between individual underfloor heating circuits while providing flow control and system balancing.

Underfloor Heating Mixing Valves

Control the water temperature entering compatible wet underfloor heating systems.

Underfloor Heating Pumps

Circulate heated water through underfloor heating manifolds and individual floor circuits.

Pipe Cutters

Create clean, square cuts in multilayer pipe before fitting preparation.

Multilayer Pipe Reamers

Calibrate and prepare freshly cut PEX/AL/PEX pipe before inserting compatible fittings.

Pipe Clips

Secure pipework neatly during plumbing and heating installation.

Underfloor Heating Controls

Control individual heating zones using thermostats, wiring centres and thermal actuators.

Why Buy PEX/AL/PEX Multilayer Composite Pipe from Kudos Trading?

Kudos Trading supplies professional plumbing, heating and underfloor heating products for installers and homeowners throughout the UK.

Furthermore, our extensive range makes it easy to purchase multilayer pipe alongside manifolds, Eurocones, valves and installation tools.

When you order from Kudos Trading, you’ll benefit from:

• Quality plumbing and heating products
• Competitive UK prices
• Fast nationwide delivery
• Expert technical support
• Extensive product availability
• Friendly customer service
• Over 25 years of industry experience

Frequently Asked Questions

What is PEX/AL/PEX pipe?

PEX/AL/PEX is a multilayer composite pipe. It combines inner and outer PEX layers with a central aluminium layer to provide flexibility, strength and dimensional stability.

What does PEX/AL/PEX mean?

PEX refers to cross-linked polyethylene, while AL refers to aluminium. Therefore, PEX/AL/PEX describes the pipe’s polymer-aluminium-polymer construction.

Does PEX/AL/PEX have an oxygen barrier?

Yes. The aluminium layer provides an effective oxygen barrier. Consequently, the pipe works particularly well in suitable closed-loop heating systems.

Can PEX/AL/PEX be used for underfloor heating?

Yes. PEX/AL/PEX is widely suited to water underfloor heating. Its flexibility, oxygen barrier and shape retention make it particularly useful for floor heating circuits.

Can PEX/AL/PEX be used with an underfloor heating manifold?

Yes. Compatible Eurocone connectors can connect the pipe to an underfloor heating manifold. However, always match the Eurocone to the exact pipe diameter and wall thickness.

Can PEX/AL/PEX be used for plumbing?

Suitable approved PEX/AL/PEX pipe can be used for hot and cold water plumbing. However, always check the specific pipe approvals and intended applications before installation.

Can PEX/AL/PEX connect to a plumbing manifold?

Yes. Multilayer pipe works particularly well with manifold plumbing systems. Furthermore, individual pipe runs can reduce the number of concealed connections throughout a property.

Can PEX/AL/PEX be used for central heating?

Yes. Suitable PEX/AL/PEX pipe can carry heating water in radiator and other compatible central heating systems.

Is PEX/AL/PEX suitable for heat pumps?

Yes. Correctly specified multilayer pipe can form part of compatible heat pump heating systems. However, installers must size the pipe correctly for the required system flow rates.

Does PEX/AL/PEX retain its shape when bent?

Yes. The aluminium layer gives the pipe excellent shape retention. Therefore, formed bends remain more stable than with many all-plastic pipes.

Does PEX/AL/PEX expand when heated?

All pipe materials experience some thermal movement. However, the aluminium layer significantly improves dimensional stability compared with many conventional plastic pipes.

Do I need to ream PEX/AL/PEX pipe?

Yes, where required by the fitting system. Correct calibration and reaming restores the pipe end after cutting and helps protect fitting seals during assembly.

Can I cut PEX/AL/PEX with a normal pipe cutter?

Use a cutter specifically suitable for multilayer composite pipe. This helps produce a clean, square cut ready for calibration and fitting.

What fittings do I need for PEX/AL/PEX?

Use fittings designed for the exact outside diameter and wall thickness of your pipe. Suitable systems can include Eurocones, press fittings and other approved multilayer connections.

Can PEX/AL/PEX be bent by hand?

Many smaller multilayer pipe sizes can be carefully formed by hand within their specified bend radius. However, tighter bends may require a suitable bending tool or former.

Is PEX/AL/PEX better than standard plastic pipe?

The best choice depends on the application. However, PEX/AL/PEX offers excellent shape retention, an integrated aluminium oxygen barrier and reduced thermal expansion.

Related Products

• Plumbing Manifolds
• Plumbing Manifold Ball Valves
• PEX/AL/PEX Eurocones
• Underfloor Heating Manifolds
• Underfloor Heating Mixing Valves
• Underfloor Heating Pumps
• Pipe Cutters
• Multilayer Pipe Reamers
• Pipe Clips
• Underfloor Heating Controls
• Pipe Jointing Products
• Plumbing & Heating Fittings

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