Nägel, HM 2011, 'Cost and energy-efficient pumping of paste and thickened tailings — the pump ace — quintuplex double hose-diaphragm pump', in R Jewell & AB Fourie (eds), Paste 2011: Proceedings of the 14th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 453-462, https://doi.org/10.36487/ACG_rep/1104_39_Nagel (https://papers.acg.uwa.edu.au/p/1104_39_Nagel/) Abstract: Tailings disposal systems nowadays operate at much higher solids concentrations than previous installations. This change is primarily due to economic and environmental considerations. On one hand, highly concentrated systems offer a great many benefits, but on the other they impose high demands on the mechanical equipment. Positive displacement pumps are typically applied for such duties. Hydraulically actuated double hose-diaphragm pumps allow for pressures up to 320 bar and offer decisive advantages versus traditional piston pumps, hydraulically activated piston pumps or diaphragm pumps. With an ideal linear flow path they are especially conducive to the handling of paste and tailings at minimum wear, be they highly viscous, corrosive and/or erosive. The check valves (easily removable cassette design) are the only actual wearing parts and available as single or double units. Backflow leaks resulting from jammed solids are reliably prevented. Double hose-diaphragm pumps offer maximum efficiency and are almost exclusively of triplex up flow or down flow design, using crankshafts that are offset by 120 degrees. By this means, continuous slurry flow is ensured and sedimentation avoided. For high flow rates, single-acting quintuplex pumps provide for the further reduction of kinematic irregularities.