Butterfly Valves - Flow Coefficients Cv
The table below can be used to indicate butterfly valves and their flow coefficients at different open (or closed) positions. Manufacturers data should always be checked before actual use.
| Valve Size | Flow Coefficient - Cv | ||||||
|---|---|---|---|---|---|---|---|
| Openness (disc angle) | Maximum flow velocity (ft/sec) | ||||||
| inches | mm | 90 deg (wide open) | 70 deg | 50 deg | 30 deg | ANSI 150 | ANSI 300 |
| 2 | 50 | 85 | 65 | 35 | 15 | 90 | 90 |
| 2 1/2 | 65 | 160 | 120 | 65 | 29 | 80 | 90 |
| 3 | 80 | 260 | 195 | 104 | 47 | 80 | 80 |
| 4 | 100 | 475 | 356 | 190 | 86 | 80 | 80 |
| 5 | 125 | 770 | 577 | 308 | 139 | 80 | 80 |
| 6 | 150 | 1125 | 844 | 450 | 203 | 75 | 80 |
| 8 | 200 | 2110 | 1583 | 844 | 380 | 70 | 75 |
| 10 | 250 | 3350 | 2513 | 1340 | 603 | 60 | 70 |
| 12 | 300 | 4800 | 3600 | 1920 | 864 | 50 | 60 |
| 14 | 350 | 6900 | 5175 | 2760 | 1224 | 50 | |
| 16 | 400 | 9000 | 6750 | 3600 | 1620 | 50 | |
| 18 | 450 | 11800 | 8850 | 4720 | 2124 | 50 | |
| 20 | 500 | 14300 | 10725 | 5720 | 2574 | 50 | |
- 1 ft/s = 0.3048 m/s
Related Topics
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Control Valve terminology, bodies, trim, flow characteristics, Cv and Kv sizing, noise, actuators, positioners and more.
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