Keeping stakeholders satisfiedmaking a profit for shareholders and observing tight regulation is a constant juggling act for water companies. As a resourcewater is becoming increasingly preciousmeaning those responsible for managing its supply are continually under the microscope.
In the UKfor exampleregulator Ofwat’s recent consultation on its forward programme to 2009 drew the following response from Water UK: “Companies have a responsibility to challenge their own operational and business strategies and practices – both to ensure delivery of expected outputs and efficiency in the next five yearsand to ensure longer term sustainability. For instanceclimate changehousing growthconcerns about water resources and reliability of suppliesaffordability and financing pressures are driving companies to search for technological changes and new ways of managing assetsinnovations in charging methods and financial structures – and to understand better their own customers’ priorities.”
Driving costs down in the purification and production areas means that savings can be invested back into such programmes as leakage reduction and pipe replacement. One of the major cost-cutting areas is in equipment usage – making long-termwell-informed decisions on pumping technology can mean a massive reduction in labourmaintenance and ease of use – as well as finances (Fig.1).
For the water industrypump selection is a complex task. With so many products to choose fromsuch varying costs and so many specific requirementsit’s no easy decision. In the pastthe multitude of options available has meant that purchasers made their choice by selecting the cheapest design for the short term – often to their long-term detriment. However with maintenance costs risingmore purchasers are considering whole life costs and realising the false economy of the cheapest up-front option is no longer a viable decision.
In comparison with other pumping technologies such as diaphragmcentrifugal and submersiblesthe relative lack of complexity in peristaltic pumping technology makes it increasingly the first choice in the water and wastewater sector due to its simplicity of designease of maintenance and long-term cost effectiveness.
These high flowhigh pressure pumps are used in various stages of wastewater treatment including metering and transferring a wide range of harsh and aggressive materialsand have the ability to provide extremely accurate dosing measures – they can deliver either a teaspoon or a tanker load of chemicals and at variable rates according to weather conditionstime of year and so on – and pumping volumes from microlitres to gallons an hour.
Intelligentautomated systems are vital for cutting labour hours and cost efficiencyand the peristaltic pump is able to deliver reliableconsistent results 24 hours a dayseven days a weekwithout operator intervention.
Also unlike other pump technologieswhich have tight tolerances or interference fits of the wetted rotating partsperistaltic pumps keep extremely corrosive chemicals such as ferric chloridesodium hypochlorite and abrasive fluids like sludgeslime and powdered activated carbon (PAC) slurries from wearing the pump's rotating components. In facta properly selected heavy-duty pump hose never fails due to abrasive wear; it only fails due to the total number of occlusions seen in a specific application. Regardless of productwhether it is abrasive grit in a grit removal systemthickened sludgelime slurry or nonabrasive polymerthe hose life is the sameoffering the kind of flexibility that is likely to become a necessity for water companies in the near futureas regulations become more restrictive.
The fast approaching Water Framework Directive is set to include far stricter regulations on chemical dosingmeaning that accuracy in this area is going to be more essential than ever before – possibly instigating a flurry of new purchasing for those companies with below standard equipment.
Uncertainty and risk surrounding dwindling supply and new regulation is forcing water companies to look to the future and do the same with their equipment. Life cycle costing (LCC) analysis is seen as a strategic management tool and in the case of the water sector it is an essential part of budgeting and planning – driven by the sector’s distinct characteristics of increasing demandlimited resource and financial constraints.
Looking at the life span of a product and weighing up the overall costs is becoming common practice – particularly in this constantly changing environment. No longer dominated by initial costor energy efficiency figuresthe water industry is starting to realise that money saved on repairsreplacements and resources far outweigh any short-term gain from cheaper pumps that hold an increased risk of breakdown (Fig.2).
In the UKall water companies have an obligation to provide a 25-year resource planrevised each yearin which they forecast demand and supply and set out how they intend to maintain security of resource for their customers over this period of time. Knowing that they have reliableefficient pumping technology which can adapt to future regulations means that the cost of replacing equipment can be kept to a minimumas can predicted labour and maintenance rates.
Forecasting future business variables such as climate change impacts mean that companies have to incorporate risk and uncertainty into their long term planning strategies. Conventional pumping technology uses valvesseals and associated pipework. Indisputably this means that there are more parts that can go wrong. When considered in terms of LCCwhich looks at all the components that make up the total cost of pump ownership – including both the internal parts of the product itself and external ancillary equipment – peristaltic pumps have gained growing recognition and uptake across process industries.
Phil Bolton is Water Industry Specialist at Watson-Marlow Bredel Pumps. For more informationvisit
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