September 2020

Focus on: Pumps & Valves Process, Controls & Plant Sepember 2020 www.pwemag.co.uk Plant & Works Engineering | 25 flow rate coming out of the purple square in is essence greater than the green area. The power input is however the same. Finally, we take a complete system view and include the losses in the recirculation line as well as the losses in the regulating valve on the line to the second tank (the red outline). What might have looked like a reasonably good Fig. 2 Efficiency of a pump measured on a component basis (purple box) based on the ratio between the pump’s input and output. The system view includes a re- circulation line as shown by the green box. Looking at the complete pumping system using a total system approach is illustrated by the red box system when measuring the components in the purple square can be viewed as an extremely low efficiency system when looked at using the systems approach illustrated by the red outline. To do this we need to define the system demand, i.e. the minimum pressure, flow rate and subsequent energy for the pumping system to work. To understand the knowledge and tools required to assess the system, industry spent many years developing the international standard ISO 14414 – Pump System Energy Assessment. There are many exciting energy use improvement programs being developed around the world, but in Europe we have the Energy Efficiency Directive, which mandates energy audits in Systems. For the electrical energy savings identified in pumping systems to be fully achieved, there needs to be a far stronger emphasis on the ‘systems approach’ and a commitment to make this happen from both the pump industry and its final end users – those that will ultimately benefit from lower energy bills. Europump would like to thank Steve Schofield, CEO, British Pump Manufacturers’ Association for his help in compiling this article. For further information please visit: www.europump.org Call 01664 567226 for more information www.dualpumps.co.uk Supplying quality products & service since 1975 UK Official Distributor Since 1983 REQUEST YOUR COPY Dual Pumps 178x124 Sept.indd 1 26/08/2020 08:29:35