Multiple Benefits of multi-layered piping
Antony Corbett, Product Manager at Geberit, looks at the challenges facing building services engineers during the material selection process and why multi-layered piping is proving to be a popular choice for the supply of heating and potable water.
Selecting the right material is critical when it comes to designing a building’s supply piping system.
Challenges in choice
A safe, compliant, and effective supply piping system starts with selecting the right product for the right project. It will support building efficiency, help meet applicable regulations, minimise running costs and deliver a better environment for the end-user. It can also facilitate a more efficient installation, saving labour time and costs in the process.
Get it wrong, however, and it can result in anything from faulty fittings and pipe bursts, to corrosion and hygiene issues such as limescale build-up or risk of Legionella. At a time when construction output prices continue to rise and contractors are facing additional pressures and restrictions, such costly (yet completely avoidable) errors could be detrimental.
When it comes to hot and cold potable water supply systems, copper and flexible plastics have both proved their worth over the years.
Copper has been used extensively since the 1940s (and particularly since the 1969 ban on lead piping) thanks to a number of benefits including inherent strength and stability, resistance to the effects of heat and pressure, not to mention hygiene properties. Plastic piping came to the fore in the 1980s and 1990s, providing an inexpensive alternative to metal pipework systems.
Both remain popular, but there is another option which combines the benefits of both in delivering a strong yet flexible solution: multi-layer composite pipe systems.
Strong and flexible
The product typically consists of three distinct layers, including an inert outer plastic layer usually made of polyethylene (PE-RT II), which protects against corrosion and mechanical damage. This encases a central aluminum layer ensuring that the pipe can be bent into position and remain in shape, which in turn encases a final plastic layer, usually made from the same or similar material to the outside layer.
These systems were first introduced to the UK market in the 1970s and the technology has often been reserved for industrial applications, including compressed air and water. However, multi-layered piping is now used as a single solution for all potable water and heating supplies on both light commercial and domestic projects.
Multi-layer piping is corrosion-resistant, hygienic and is not liable to oxygen diffusion through the pipe wall, which minimises the risk of damage by oxygen corrosion elsewhere in the system. It has a reduced thermal expansion compared to most plastics and retains heat due to its material make-up. It delivers a system which is stronger and more durable than plastic piping, yet lighter and more flexible than metal options. It is a winning combination that can not only ensure a more efficient installation but overcomes many of the specification challenges that could lead to costly errors or faults later down the line.
Opting for multi-layer piping systems can also result in a more efficient installation process. Such systems use press-fitting and so eliminate the need for hot works on-site. The only tools needed to form a reliable, tight and durable connection are a cutter, deburrer and press tool.
Press-fitting on site carries a lower insurance premium due to the absence of a working flame. This means fewer health and safety considerations which can minimise the risk of damage to existing fittings and fixtures and the surrounding areas. It also means no need for delays to allow for a cool down period.
Meanwhile, multi-layer piping systems can be adjusted to the on-site conditions – and even manipulated to follow the line of any curved architectural features in buildings. Pipes of 16mm and 20mm pipes can be bent effortlessly by hand and larger diameters can also be bent without risk of de-lamination or kinking by using an appropriate tool. This can significantly reduce the number of fittings required and can, therefore, increase installation speed – in many cases this can result in a significantly lower overall project installation cost when compared to copper pipes.
Keeping an open mind
Offering the very best of plastic and metal piping, multi-layer piping systems can help tackle head-on the common challenges of material selection. With these challenges in mind, it is essential that building services engineers keep their options open to new materials, products and ways of working.