Modern Building Services

14 MODERN BUILDING SERVICES APRIL 2021 FEATURE PIPED SERVICES & PUMPWATER PIPED SERVICES S electing 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. Material world When it comes to hot and cold potablewater 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 tomention hygiene properties. Plastic piping came to the fore in the 1980s and 1990s, providing an inexpensive alternative tometal 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. Specification challenges 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. 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. Multiple Benefits of multi-layered piping