Water & Wastewater Treatment Magazine
Issue link: https://fhpublishing.uberflip.com/i/741165
www.wwtonline.co.uk | WWT | NOVEMBER 2016 | 11 shortfall in efficiency of between 12.5 and 20 per cent because they are incorrectly specified. The situation is worse for pumps that handle more unusual or complex media, such as chemicals or pharmaceuticals. To help with changes in duty and assist with energy reduction many pump manufacturers are now promoting the use of Variable Speed Driven pump systems - frequency drive being the most prominent system used. By using VSDs, you in effect combine electrical and mechanical principles. The addition of the latest controls or ancillary equipment can o€en help boost efficiency and enable pumps to meet changes in demand at a fraction of the cost of building a new system from scratch. In some cases, simply upgrading a pumping system can result in energy savings of up to 50%. The importance of good design Maintenance and energy consumption represent by far the two most significant costs throughout the life of a pump. The answer to minimizing these costs lies in ensuring a well-designed pumping system, where the pump is specified as correctly as possible to the demands of the appli- cation. The energy consumption and efficiency of a pump is closely linked to the way that a pumping system is designed and operated. Every pump manufacturer can, or should, supply characteristic curves for their equipment illustrating pump performance under given conditions. These curves demonstrate the inter- relationship between discharge capacity, pump head, power and operating efficiency. The BPMA and its members have been involved in the writing of Europump guides to assist users with their selection and operation of pumping equipment. Looking at the possible energy savings in the entire pumping system, the BPMA in 2010 created the CPSA scheme (Certified Pump System Auditor). This is a new industry specific professional qualification developed by an established and highly regarded body within the industry. The objective of the scheme is to help improve the levels of professionalism in the sector by creating a universally recognised and respected industry 'standard' for individuals assessing the performance of a pumping system. Expert view sponsored by It is regularly reported in the news that one of the water utilities' main objectives is to reduce the amount of leakage from their distribution systems. When it comes to leaks caused by corrosion, they already have the right tools handy to prevent many of them when the pipes are originally installed. All they really need to do is to ensure that these tools are used properly by asking for adequate product application training. I know that leaks can occur for lots of reasons. Broken pipes or couplings through mechanical damage or ground movement is a possible cause but one of the most common reasons must be corrosion. New pipe lengths are usually supplied with a factory applied corrosion prevention coating but this can get damaged during handling, fitting, backfilling etc and most pipe couplings require nuts and bolts to fasten them and are extremely vulnerable to corrosion. So despite factory applied coatings there is almost always a need for field applied corrosion prevention. To overcome this need the P1 and P2 Civil Engineering Specifications for the Water Industry 5th Edition were issued which cover the protection of ferrous pipes, joints and fittings using anti-corrosion and sealing materials prior to burial. Winn & Coales (Denso) Ltd have manufactured and supplied anti- corrosion systems that comply with both the P1 and P2 specifications Care against corrosion Keith Corfield Sales Manager Winn & Coales (Denso) Ltd for many years now and when the systems are applied correctly our archives show that they are extremely effective at providing long-term corrosion prevention. The Denso system comprises (a er cleaning), an initial coat of Denso Paste over the entire area followed by the use of Denso Profiling Mastic to fill voids and form a smooth profile prior to wrapping. The whole joint is then wrapped with Denso Tape (petrolatum) for the P1 spec or with Densoclad Tape (bitumen laminate) for the P2 spec, where a tougher level of protection is needed. The system is very easy to apply but care must be taken to use the product correctly, particularly when filling voids with profiling mastic. It is this stage that sometimes gets missed out by contractors with grave consequences for the coupling as wrapping our Denso Tape over a void will create a pocket where water can enter, build up and lay, causing rapid and extensive corrosion to the surrounding area. The enormous wasted cost and serious environmental issues that are caused by incorrect or incomplete system applications affect everyone and we at Denso are very keen to make sure our products are always applied correctly to meet the required specifications. To remedy this situation we offer free product application training, either on site or at our training centre in London. We are also happy to work closely with the utilities/contractors producing free customised instructional literature and application videos etc. For more information on Denso Products and training contact our head office: the full address and contact details can be found at www.denso.net. Top tips for getting it right: 1) Choose the right pump for the right application. Centrifugal pumps are generally suited to fast flowing or low viscosity liquid applications where the pressure is relatively constant; positive displacement pumps are particularly ideal for high viscosity applications, as they are better able to maintain a constant rate of flow. 2) Ensure there is sufficient pressure for the pump to work effectively. 3) Is the pump positioned in the correct place? Where a pump is positioned within a pipeline can greatly affect its performance. 4) Don't just purchase on cost alone; when it comes to selecting a pump, cheapest is by no means best. 5) Always take the pump manufacturer's advice. It's surprising how many customers don't take advantage of the expertise available from the manufacturer on performance.