Optimum centrifugal pump for suction lift

2 min read
The new Hidrostal end suction pumps installation.
The new Hidrostal end suction pumps installation.

The digital edition of the magazine is distributed free of charge to readers who meet our qualifying criteria. You can apply to receive your free copy by completing this short registration form.In order to meet the long standing self-priming needs for Redditch WWTW, Hidrostal proposed a solution which utilised a lot of the existing equipment used such as the pump house, pipework, plinths and control panel. The simple solution represented a good value engineered and upgraded solution with a good low risk CDM compliance.The static priming tank system was built around the Hidrostal screw centrifugal pump, designed for its high efficiency and low NPSH capabilities, an optimum centrifugal pump for suction lift applications. The improved efficiency meant the new Hidrostal pumps were able to reduce the installed KW size. One 11 KW Hidrostal pump was capable of pumping more than two of the originally installed 18.5 KW self-priming pumps.Static priming tankDue to the higher efficiency of the Hidrostal system duty/standby was now possible, compared with the original duty/assist/standby layout. The static priming tank was installed into the position of the original middle assist pump, even making use of its concrete plinth. See photos overleaf.On this installation Hidrostal supplied and installed two identical end suction bearing frame pumps of model E06U-MMN3R+EFM1X-M160 fitted with 11 KW, 4-pole, WEG, WIMES high efficiency motors. The two pumps were installed alongside a suitable sized and fabricated static priming tank to generate a suction lift of 2.3 m. The installation now only required a single suction pipe from the wet well to the static priming tank. This in turn provided a new suction connection to the new pumps. Two of the original suction lines were removed from the pump station layout, improving access. The discharge pipework was maintained apart from the pipework in the redundant pump position. This was removed and blanked off, again improving access.The Hidrostal above ground solution was compared with a number of submersible wet well proposals. The above ground solution was selected because it negated the risks of entering and lifting around the wet well, for both the installation and on-going maintenance requirements associated with submersible pumps.Since commissioning Hidrostal in June 2012, Redditch WWTW is very satisfied with the solution and system performance. A follow up in April 2013 and later in October 2013 saw John Ratheram, Service Delivery Manger for Redditch area report “All working fine with no issues. I am very pleased with the improved reliability and performance”.Finally the long standing self-priming issue has been solved at this part of the works. The original 50 l/sec pump duty, delivered from a pair of unreliable duty/assist self-priming pumps, is now being handled by a single and reliable Hidrostal duty pump with an output of 58 l/sec.

The digital edition of the magazine is distributed free of charge to readers who meet our qualifying criteria. You can apply to receive your free copy by completing this short registration form.