Testing role for pumps

Until recently, turbidity testing at the Pontsticill Water Treatment Works in the Brecon Beacons National Park relied on the use of bellows pump technology.

However, the inherent introduction of air in the samples was undesirable and led to false readings.Now, Watson-Marlow's Qdos 30 metering pumps provide good suction lift and do so without air locks.

"This is a clean water site and the quality of sample is very important," states Marek Cegielski, a process scientist and manager at Dwr Cymru Welsh Water. "In the past we've tried other types of turbidity monitoring devices, such as dip probes, but without much success. We've even used bubble traps in conjunction with our bellows pumps, but we still fell short of 100% reliability. Of course, eliminating the need for bubble traps was one of the attractions of replacing one of our bellows pumps with the new Qdos 30 from Watson-Marlow." The Qdos 30 metering pump at Pontsticill is taking elutriates from a DAF (dissolved air flotation) filtration plant and lifting it about 3m before it passes through a turbidity meter and returns by gravity back into the flow. At this point the water has already been subjected to coagulation, flocculation and flotation, and is ready for final filtration processes.

Capable of delivering flow performance from 0.1 to 500ml/min, the pump gives the water company a steady flow speed of 280ml/min.