Water & Wastewater Treatment

THE PUMPING STATION - PUMP AND VALVE SUPPLEMENT 2017 15 In Depth: Valves and fl ow control Pressure Points A familiar challenge for water companies when dealing with incidents in the distribution network is which ones to prioritise. Complaints resulting in SIM points, possibly from a major or less obvious burst incident, will understandably take priority. At the regional Intelligent Control Centre (ICC), judgement calls are made all the time. A large sudden loss of water will soon have the phone ringing o• the hook and a team sent out to rectify the situation as quickly as possible. But if an 'alarm' is considered minor, such as a valve dri- ing o• pro€ le, it will probably be put into the next maintenance schedule. When you bear in mind that one water company we worked with recently was experiencing on average around 15,000 alarms per day, that would appear to represent a great many continuing issues in the network. Some of these problems will simply be due to the age of the network. Historically, the networks were well designed by vastly experienced hydraulic engineers who had no hesitation in installing air valves where they knew they would be required. It must have been a much quieter environment in those days, but during the past 30 years or so, issues such as water hammer have become the norm. As with anything in life, it is only when you have the full picture that you can gain a true understanding. In our role, once we've helped establish security of supply and a calm network to eliminate those unnecessary bursts, we work closely alongside a water company or industrial user to identify Building a smarter network need not be expensive – a rst step is to establish a calm pressure pro le, writes Craig Stanners the parts of the network that have problems. Typically driven by customer complaints, we look € rst at the DMA (District Metering Area), then to the larger DMZ (District Metering Zone) and trunk main systems. Understanding the pressure pro€ le is vital. At the ICC, monitoring will show spikes on a network, although these won't necessarily create alarms. For leak detection using all manner of technology, including listening devices, it sometimes seems like no expense is spared, but I would challenge any water company to look at the signi€ cant € nancial and operational bene€ ts of protecting and thus increasing the life of existing assets. Fragmented pressure pro€ les in the network need removing. They are a constant burden and strain on ageing infrastructure. Bournemouth Water was very forward thinking in this department, redesigning much of its network to use our intelligent network calming and pressure management valves to reduce leakage and burst frequencies. And they did this cost-e• ectively, even though I am going to tell you (not surprisingly!) that our Pressure Reducing Valves (PRVs) are of a very high speci€ cation. Initially, 13 of the company's District Metering Areas (DMAs) were set up, followed by a further 50. The project By Craig Stanners Director, IVL Flow Control An air valve in detail (bottom right) and in situ (main)

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