UK first for Glasgow leakage
A pressure management strategy to reduce leakage in Glasgow involved a 400mm C-Valve from Plasson. The company's sales and marketing manager, Simon Merckel, reveals how
The area serves approximately 24,000 properties and acts as an entry point for potable water to the city centre of Glasgow and a large area south of the Clyde. Known as a problem area in terms of leakage, the site had not previously been pressure controlled due to the wide operational requirements and low pressures in some areas.
The valve was specified for the project as there was a need for a low head loss valve at peak flow times as conventional pressure reducing valves have a limited standing head loss of between three and eight metres when fully open, preventing their use in this location due to non-compliance with regulated pressure standards. According to Scottish Water, the C-Valve has a head loss that is less than the tolerance of the loggers measuring the valve when fully open, making it the most effective equipment for an installation of this type.
The objectives prior to installing the C-Valve were to reduce leakage, prevent pressure non-compliances due to valve restrictions and allow for servicing without by-passing through non-pressure managed pipe. The C-Valve ensures a constant pressure management system and allows for emergency flows and pressure modulation through a third party controller adjusting the valve. Following a period of observation where 2.3Ml/d were saved, a Technolog Modulo Controller was installed to regulate pressure according to the actual flow through the valve, taking a further 6m off the pressure during periods of low flow and resulting in an additional 1.4Ml/d saving. Installing the C-Valve has resulted in an impressive 3.7Ml/d total saving, much more than the 2.7Ml/d expected from modelling.
Commenting on the installation, Jake Ratter at Scottish Water said: "We have seen impressive initial water savings since installing the valve and are extremely pleased with the results. The total leakage saving per day is 3,700m³."
The installation also demonstrates an additional benefit of burst reduction in the city centre due to a more even pressure profile in the old and delicate network, reducing maintenance and cost due to a lower frequency of mains burst repairs. The modular design of the Plasson C-Valve system means that external filters can easily be serviced and the isolation valves enable rapid isolation of each control valve element prior to any servicing and the control plate is easily serviced or exchanged if required. The C-Valve delivers a reliable and stable pressure with minimum head loss and maximum reliability. The modular design and versatility means solutions can be tailored to suit specific needs with ease of installation, operation and maintenance.