Min. purge Nominal pipe Area velocity diameter (mm) (m2) (m/s) 150 0.02 0.6 200 0.03 0.6 250 0.05 0.6 300 0.07 0.6 350 0.1 0.6 400 0.13 0.6 450 0.16 0.6 500 0.2 0.6 550 0.24 0.6 600 0.28 0.6 650 0.33 0.6 700 0.39 0.6 750 0.44 0.6 800 0.5 0.6 850 0.57 0.6 900 0.64 0.6 950 0.71 0.6 1000 0.79 0.6 1050 0.87 0.6 1100 0.95 0.6 1150 1.04 0.6 1200 1.13 0.6 No. of Nitrogen Minimum flow rate cyclinders required (m3/min) in parallel 0.6 1 1.1 2 1.8 2 2.5 3 3.5 4 4.5 5 5.7 6 7.1 8 8.6 9 10.2 11 12.0 12 13.9 14 15.9 16 18.1 19 20.4 21 22.9 23 25.5 26 28.3 29 31.2 32 34.2 35 37.4 38 40.7 41