When it comes to choosing a multilayer composite pipe (MLCP) for heating and plumbing, two names often come up: PEX-AL-PEX and PERT-AL-PERT. At first glance they look the same—both built with a strong aluminium core sandwiched between plastic layers—but the type of plastic makes a real difference in how the pipe performs on-site.

So, which one is right for your project? Let’s break it down.

What Are PEX-AL-PEX and PERT-AL-PERT ?

Both pipe types are designed for Suitable for hot & cold water plumbing as well as heating systems. The aluminium middle layer adds rigidity, strength, and acts as an oxygen barrier, protecting heating systems from corrosion. The difference is in the outer and inner layers:

• PEX-AL-PEX uses cross-linked polyethylene (PEX).
• PERT-AL-PERT uses raised temperature polyethylene (PERT).

That single change affects flexibility, recyclability, and ease of installation.

Key Differences at a Glance

Feature	PEX-AL-PEX	PERT-AL-PERT
Plastic Material	PEX (Cross-linked Polyethylene)	PERT (Raised Temperature Polyethylene)
Flexibility	More rigid	More flexible, easier to bend
Cross-Linking	Yes – adds strength but reduces recyclability	No – remains thermoplastic and easier to recycle
Temperature & Pressure	Up to 95°C, 10 bar	Up to 95°C, 10 bar
Ease of Installation	Trickier in tight spaces	Simpler, quicker handling
Best Suited For	High-temp, high-pressure systems	Underfloor heating, radiator connections, plumbing and heating systems

PEX-AL-PEX: Solid but Stiffer

PEX-AL-PEX has been around a long time and is known for its durability. Cross-linking gives it extra chemical resistance and strength, but it also makes the pipe stiffer. That rigidity can be useful in certain high-pressure or fixed installations, but it can slow things down during tricky runs or retrofits.

PERT-AL-PERT: Flexible, Reliable, Installer-Friendly

PERT-AL-PERT delivers the same performance ratings as PEX-AL-PEX—handling up to 95°C and 10 bar—but with greater flexibility. That makes it easier to route through floors, ceiling space and around corners, saving time and hassle on-site.

Because PERT is not cross-linked, the pipe remains a true thermoplastic. This not only makes installation smoother but also improves recyclability compared to PEX.

That’s why you’ll see PERT-AL-PERT widely used in underfloor heating, radiator connections, and plumbing and heating projects—the flexibility helps during installation without compromising reliability.

At LoCO₂ Heat, we stock and supply a wide range of PERT-AL-PERT because it strikes the right balance for most real-world projects; versatile, and installer-friendly.

Not sure what’s best for your job? Get in touch for advice, or have a look at our MLCP range to see the options available.