FLUSHING & CLEANING VELOCITIES... SIZE VELOCITY FLOW RATE [mm] [inch] [m/s] [fps] [l/s] [gps] 15 0.5 0.96 3.14 0.20 0.53 20 0.75 1.00 3.28 0.37 0.98 25 1 1.03 3.38 0.60 0.16 32 1.25 1.06 3.47 1.08 0.28 40 1.5 1.08 3.54 1.49 0.39 50 2 1.11 3.64 2.47 0.65 65 2.5 1.15 3.77 4.29 1.13 80 3 1.17 3.84 6.01 1.59 100 4 1.21 3.97 10.5 2.77 125 5 1.24 4.06 16.4 4.33 150 6 1.26 4.13 23.8 6.29 200 8 1.31 4.30 43.9 11.6 250 10 1.35 4.43 71.9 19.0 300 12 1.37 4.50 103 27.2 *sizes over 300mm = design flow rate + 10% or use different method of cleaning constructandcommission.com