Tackling micro-organisms and biofilms in water systems has long been an issue when managing legionella bacteria, which is essential to maintain a healthy water supply.
Craig Norman, Proposition Development Director at Aliaxis, outlines how plastic pipe systems are better equipped to combat legionella than copper or other metal pipes.
Legionella bacteria, which can prove fatal, can build up when standing water remains and is not flushed out of a plumbing system, particularly in a ‘dead leg’ containing stagnant water. Failure to do this increases the risk of the growth and spread of legionella and other biofilm-type bacteria.
Therefore, the nature of the materials chosen to supply water to a building can have a direct impact on the risk of this serious type of pneumonia, contracted by inhaling airborne water droplets containing viable Legionella bacteria.
Since the introduction of polyethylene (PE) in the 1950s, there has been much debate as to whether plastic pipe systems provide a better alternative to copper or metal pipes.
Plastic pipes, with their smooth inner bore, help to manage potential bacterial contamination of the water by eradicating such problems as scaling and corrosion. In comparison, a metal plumbing pipe with a rough inner surface can create the conditions for bacteria, such as legionella, to flourish and release into the water supply in harmful quantities.
According to the Health and Safety Executive, the bacteria multiply where temperatures are between 20-50°C and nutrients are available. The bacteria are dormant below 20°C and do not survive above 60°C.
Plastic pipework solutions can operate in temperatures up to 70°C for hot and cold domestic systems, with legionella bacteria destroyed at 60°C.
Water in metal pipes can build micro-organisms and biofilms faster than a plastic pipe. This can lead to much higher temperature shocks and require harsh chemicals to clear the pipe of risk. Metal pipes can support usual operating temperatures of between 85°C and 95°C.
Whilst architects and contractors are increasingly turning to plastic pipes as a water delivery solution, the majority of the installed pipes in the UK market remain copper-led. Therefore, a significantly wider use of plastic will only come through the specification route, where the time and money saved on installation, the health benefits, and durability and longevity to support cold and hot water will all form part of the equation.
As a total solutions provider, Aliaxis offers a range of solutions for applications throughout the building services, infrastructure and industrial sectors, with expert technical teams on hand to ensure the right product is chosen for the right project every time.