stvvalves

  Even though we work on a metric system, measures of flow are commonly given as a CV value which is an; Imperial measure flow in US gallons per minute of water at 60° fahrenheit with pressure drop of 1 psi across the valve. Below is a table of the flow rates for Butterfly Valves at different opening stages between zero degrees (fully closed) and ninety degrees (fully open). Please note that a CV value is not a linear progression so it cannot be extrapolated out just by looking at the values, it is really just meant to give you a comparison flow rate.   Size Cv Value at different degrees of opening inch mm 10° 20° 30° 40° 50° 60° 70° 80° 90° 2 50 0.1 5 12 24 45 64 90 125 135 2 1/2 65 0.2 8 20 37 65 98 144 204 220 3 80 0.3 12 22 39 70 116 183 275 302 4 100 0.5 17 36 78 139 230 364 546 600 5 125 0.8 29 61 133 237 392 620 930 1022 6 150 2 45 95 205 366 605 958 1437 1579 8 200 3 89 188 408 727 1202 1903 2854 3136 10 250 4 151 320 694 1237 2047 3240 4859 5340 12 300 5 234 495 1072 ...

  The below CV values are used to give an indication of flow rates for ball valves . CV value is an imperial measure of flow in US gallons per minute of water at  60° fahrenheit with a pressure drop of 1 psi across the valve. This is used as a guide and is not a linear progression. V Port Ball Valves Flow Rate (CV) Valve Size Ball Angle 15% 20% 30% 40% 50% 60% 70% 80% 90% 100% 1/2" 30°* 0.1 0.1 0.2 0.3 0.5 0.8 1.1 1.6 2.2 2.6 60° 0.1 0.1 0.3 0.5 0.9 1.4 2 3.3 4.4 6 3/4" 30°* 0.1 0.2 0.5 0.7 1.1 1.8 2.4 3.3 4.5 5.4 60° 0.1 0.2 0.7 1 1.7 2.8 4 6.5 9 12 1" 30°* 0.1 0.3 0.8 1.3 2.3 3.5 5.1 9.8 8.5 10 60° 0.2 0.4 1.1 1.8 3.4 5.3 7.9 12.3 15.3 21 1 1/4" 30°* 0.2 0.4 1.1 2 3.7 5.5 8 10 13 15 60° 0.2 0.6 1.8 3 5.5 9.5 12.8 19 26 39 1 1/2" 30°* 0.3 0.6 1.6 3 5 7.5 11 14 17 20 60° 0.4 0.8 2.5 4 8 13 19 27 40 52 2" 30°* 0.4 1.2 3.8 6 10 15 23 31 43 60 60° 0.4 1.5 4.6 9 16.5 27 39 55 83 110 2 1/2" 30°* 0.4 1 4 8 12 18 28 37 62 75 60° 0.4 1.5 5 10 21 34 53 75 103...