Dear Sir, I read, with interest, Mark Reynolds’ article ‘Mind the Gap’ (LCN February 2000). Our company deals with backflow protection within the water industry and we have had a number of enquiries, due to Water Authority Regulation inspections, from laundries and care homes. One that crops up frequently is the lack of backflow protection on commercial washing machines.
Many customers are in the belief that as their washer-extractors do not have a ‘Type A’ air gap they may have to replace them. Or that as they are not fed from dedicated water supplies they will need expensive plumbing modifications. We have found that the most inexpensive way to prevent water backflow is by fitting a Reduced Pressure Zone assembly (RPZ) into their existing pipework.
Another misconception is that if a washer-extractor is fed from a break tank system with a ‘Type A’ Air gap then it conforms to the Regulations. This is not so if other ‘risk’ fittings are fed from the same break tank.
For instance, for most OPL situations the water is fed via a break tank system with a ‘Type A’ and booster pump system. This boosted system is more than likely to be used throughout a care home for showers, baths and wash-hand basins. If an air break is not provided before the connection to the washer-extractor (at point-of-use) then cross-contamination could occur and contaminate the whole water system within the care home.
Many suppliers of laundry equipment have added a break tank system to their list of supplies. These can be used at point-of-use and do indeed offer a suitable means of backflow protection for washer-extractors. However, these are not ideal for use on hot water supplies, as the reservoir of hot water will cool.
Whether or not a washer-extractor is connected to the mains supply or a tank supply, careful consideration should be given when installation is carried out. If in doubt water consumers should contact their local Water Authority or us for advice.
Richard Poskitt Director European Water Technology Halifax email: europrz@aol.com
