Water & Wastewater Treatment

26 | APRIL 2015 | WWT | www.wwtonline.co.uk ADVERTORIAL PROCESS AND ASSET CONDITION INTELLIGENCE IS KEY TO SYSTEM OPTIMISATION The reliable provision of water and sewerage services requires water companies to think and plan long term, especially when it comes to effective asset care. Water companies are under unprecedented pressure to reduce maintenance costs, but are they harnessing the power of systems and technology already in their possession to aid this, or merely reacting to problems as they occur? Guy Fitzpatrick from Xylem explains why it's time to change maintenance methodology from cure to prevention. Maintenance practices can be viewed like a set of scales, with predictive maintenance on one end and reactive maintenance (run an asset until failure) on the other. Although run to failure is a common strategy within the water industry, it can lead to high costs resulting from machine downtime and an excessive spares inventory. With a greater focus ever growing around total expenditure (Totex), proactive and predictive maintenance is being recognised as a more cost-effective solution than run to failure, but this can result in unnecessary maintenance interventions that can themselves introduce problems. For example, the simplest approach is preventive or periodic maintenance - like changing the oil on a car every three months, regardless of how much the car is driven. Scheduling an oil change every 3000 miles may seem like a good precaution to take, to ensure peak performance, whereas in retrospect, too much oil can actually damage an engine. Needless to say, predictive maintenance has become the preferred technique for critical assets in many situations, not only because it brings significant cost benefit advantages, but also because it improves the level of control that engineers can exert over the future performance of assets. However, a widespread network of water company assets, located on unmanned sites, raises a key question, how can water companies ensure they are getting the most out of their pumping systems to drive asset care? Good predictive mainte- nance programmes rely on receiving up-to-date data from the field, whether from on-line measurements, hand- held data collection or peri- odic inspections. However, it's not just a case of receiv- ing vast amounts of data, but how this data is analysed, interpreted and acted upon that will put water companies in the perfect position to know how to get the most from their assets and make the right decision for the short, medium and long term. Thames Water: A case in point In 2014, Thames Water began to further invest in ways to maintain and monitor its wastewater pumping assets more effectively. The water company wanted to further embed change its maintenance methodology to push proactive and predictive interventions, rather than reactive, and capitalise from asset and process intelligence provided from technologies already delivered as part of its ongoing asset and data improvement strategy. With this in mind, Thames Water approached Xylem to pilot a scheme to optimise more than 50 pumping stations utilising the Flygt Multismart Intelligent Pump Station Manager (iPSM) from Xylem. The Multismart is designed to manage pumping stations and provides users with the ability to manage necessary station control, communication and data requirements locally or remotely. When optimising the performance of a pumping station, it is vitally important to have a clear picture of what equipment is on site and how it performs before offering any recommendations on how it can be improved. With this in mind, Xylem introduced a step-by-step project delivery mechanism that would be used across all pilot sites that would ultimately enable Xylem to engage and collaborate with Thames Water, helping to achieve greater efficiencies across its sites. Initial site survey Working closely with Thames Water, Xylem initially created an 'Optimisation Site Survey' document to record all critical site information, whilst also focusing on the 18 Multismart key functions including control modes that are designed to monitor and control process and asset condition to minimise risk of failure, and both protect and sustain the asset condition. A team of engineers from Xylem then evaluated the entire pumping station and recorded the conditions of the site and its assets. This would include what type of well was in use and the cleanliness of the chamber, through to the performance of the pumps, and flow rates. Conducting an overall site audit allowed Xylem to obtain accurate performance data and ensure Thames Water asset registers were up-to-date. Although this process can be lengthy, it's an important step to obtaining a clear picture of current system status and where further improvements can be made. Site knowledge & data analysis Xylem was granted access to data at the Thames Water Waste Operational Control Centre (WOCC), the water company's main SCADA systems that provide alarm,

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