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Choice of pipe material will have an impact on the speed of installation and the quality of results. Antony Corbett from Geberit looks why installers are turning to multi-layered piping for heating and potable water.
A safe, compliant and effective supply piping system starts with selecting the right product. Many installers will have their own tried, tested and trusted materials, but there rarely is a one-size-fits-all approach. The requirements of a commercial project, for example, could look quite different to that of a smaller residential building.
Let’s begin by briefly looking at the main issues that need to be considered when selecting the right material for supply piping systems.
Corrosion This is the single biggest cause of breakdown in the process industries. While rare in well-designed and well-maintained systems, a significant proportion of corrosion failures occur due to some form of localised corrosion.
Hygiene Limescale build-up can allow bacteria to grow inside the piping, which can have a serious impact when it comes to the issue of drinking water. The surface roughness of the pipe must therefore be considered when selecting the material.
Cost The installed cost should include not only initial material cost, but any additional labour time, such as downtime during hot works, or specialist labour or tools needed for the job. Also important is the need to weigh up any initial costs with the overall maintenance and reliability of the system over its life cycle.
Sustainability This is important on any project and can range from opting for recyclable materials, avoiding waste to landfill, or even preventing potential theft which may necessitate duplication of materials purchased for the project.
The benefits of copper are widely known. It’s strong and is resistant to the effects of heat and pressure. Although, according to the 2018-2022 UK Pipes and Fittings Report, the market for copper has grown more slowly in recent years, it nonetheless remains a popular choice.
Plastic piping has increased in popularity over the last few decades, as it is increasingly seen as an inexpensive alternative to traditional metal pipework systems and offers advantages such as flexibility, ease of installation, and resistance to freezing.
Multi-layered piping systems are increasingly emerging as a viable option. Incorporating both plastic and metal layers, so combining the strength of copper with the flexibility and corrosion resistance of plastic, these systems have also seen significant growth in the water supply sector.
Multi-layered piping combines the advantages of both plastic and metal piping systems. These systems, such as the Geberit Mepla multi-layered piping, contains three layers: an outer plastic layer made of polyethylene (PE-RT of the second generation) which protects against corrosion and mechanical damage, a central aluminium layer which makes the pipe stable yet flexible, plus an inner layer, also made of PE-RT, for internal corrosion resistance.
The aluminium central layer of multi-layered pipes is what offers these systems their mechanical strength as well as the stability needed to ensure the pipe remains in its required position while remaining malleable enough to bend.
Meanwhile, multi-layer piping systems can be adjusted flexibly to the on-site conditions – and even manipulated to follow the line of any curved architectural features in buildings. Pipes of 16 and 20mm 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.
The option for press fitting also enables quick, simple and reliable connections with no need for hot works. The only tools needed to form a reliable, tight and durable connection are a cutter, deburrer and press tool.
The unique construction of multi-layered piping systems means that installers can also have confidence in a leak-proof system. Geberit Mepla, for example, incorporates a method of checking for missed joints. Unpressed fittings are designed to leak slightly during pressure testing (even at low water testing pressure) and can be pressed without having to drain down the entire system.
Multi-layer piping systems are 100% recyclable. Strong, durable, lightweight and flexible, these systems also require significantly less energy to fabricate, transport and install.
Perhaps one of the biggest selling-points of multi-layered systems are the hygiene properties. The plastic inner layer is resistant to cracking, aging and general wear and tear. It’s also non-reactive and corrosion resistant, so it is suitable for use in both temperature control and potable water applications. In addition, this inner layer has a low internal surface roughness – this makes it difficult for limescale and biofilm to adhere to the surface.
Multi-layer piping is continuing to grow, offering installers the very best of plastic and metal piping. We must always keep an open mind to new materials and ways of working and always look at the right product for the right project. The rate of industry innovation and product development means that anyone not doing so could be left behind.