Have you ever wondered what makes a plumbing system truly reliable for 50 years? The answer is often hidden in the details: hydraulic fittings. They connect, seal and ensure continuity between different sections of piping.

In the Valsir multilayer pipe ranges – Pexal and Mixal – fittings represent the perfect combination of materials engineering, safety and ease of installation.

What are plumbing fittings and how do they work?

A plumbing fitting is a mechanical element that joins two or more pipes, allowing the passage of water or pressurised thermal fluids.

It has a dual function:

• To guarantee a watertight seal, preventing any leaks or infiltration;
• To provide mechanical stability to the system even in the presence of temperature and pressure variations.

In a multilayer system such as Pexal, the fitting is not just a connecting component: it is an integral part of the technology, designed to interact with the pipe in a perfectly calibrated way — from thermal expansion to mechanical tightening.

Press fittings: the solution for maximum safety

The press fitting is now the standard in modern supply systems. It consists of a main body (made of brass or technopolymer) and a press bushing which, using a manual or electric press, is permanently deformed around the pipe.

The closing pressure is applied with millimetric precision using press profiles suitable for the fitting. When pressed correctly, the double seals ensure a tight seal at 10 bar and up to 95°C.

An often overlooked aspect? Certified durability. Each press fitting is tested to ensure a service life of at least 50 years, in accordance with EN ISO 21003.

Screw fittings: precision and flexibility

There are situations where quick installation and the ability to recover fittings in the event of error or disposal are added value.

In these cases, the ideal solution is a screw-on fitting such as Pexal Twist, made of brass.

These are mechanical fittings that ensure a seal through:

• a threaded core
• a tightening ring

Modular fittings: a new frontier

Pexal XL modular fittings represent an innovative engineering evolution. Instead of a single connection, each fitting is part of a modular system: a terminal (hose connector or thread), a PPS sealing collar, and a central body (elbow, tee, straight intermediate). In addition, this family of fittings allows the use of 110 mm multilayer pipes, which are used in more complex or higher density building systems.

This modular approach offers numerous advantages:

• Manual assembly, without specific equipment;
• Greater lightness and safety compared to metal;
• Prefabrication on the workbench, ideal for complex construction sites;
• Simplified logistics management (fewer components, more possible combinations).

At the heart of the system is PPSU (polyphenylsulfone), a technopolymer with very high mechanical and chemical resistance, totally inert and certified for drinking water. A material that is resistant to corrosion, lime and chemicals and maintains its stability even under thermal stress.

Safety, durability and respect for the environment

Every Valsir hydraulic fitting is designed to meet the most stringent quality standards:

• Non-toxic materials and suitable for drinking water;
• Corrosion resistance, even in the presence of aggressive chemical agents;

A fitting, therefore, is not just a technical element. It is a guarantee of efficiency, reliability and safety. And it is precisely in the hidden details — in the invisible joints behind the walls — that the quality that a system can guarantee over time is measured.