F ac t or K Solids SG 15 175 20 25 30 35 40 50 80 d 85 0 300 200 150 100 72 52 36 25 18 14 10 7 5 Diagram for reduction factor HR 01 02 06 08 09 2 4 6 2 4 6 004 1 43 4 The required duty point has now been established H total If the solid concentration exceeds 15 by volume the discharge head of the pump must be reduced By dividing the duty head with the reduction factor HR the equivalent cleanwater pump head is obtained H cv 6 The power curves for the pumps are based on clean water and these must then be multiplied by the specifc gravity of the slurry to obtain the corresponding value for slurry pumping Flygt recommends a motor with a 20 excess power margin for slurry applications due to variations in slurry 5 The pump can now be selected based on the fow and head values above H total Head total slurry H frsl F riction losses for slurry H frcw F riction losses Clean W ater H frsl Hfrcw Cf H totsl Hstat Hfrsl Head Reduction HR 1 K 1 004 H cv C v 20 30 20 H total HR Example S 18 d85 1 mm K 004