Cv Flow Coefficients of a Ball Valve
The flow coefficient or Cv flow Value is the number of US gallons of water the valve will pass through a valve with a pressure differential of 1 psi through the valve at 60F. i.e. 10 psi inlet with 9 psi at the outlet. However, the higher the pressure difference, the higher the flow and vice versa.
Kv is the metric value of Cv and is calculated as Kv = Cv x 0.865.
Cv varies with both type and size of valve, but provides a reference for comparing liquid flow capabilities for different ball valves.
The table below provides typical Cv flow values for fully open ball valves.
You can view more information about actuated ball valves here.
Ball Valve Flow Table Size / CV Flow Factors (US Gallons of water with pressure drop 1psi)
| Size BSP |
DN mm |
CV fully open |
| 1/4 |
8 |
18 |
| 3/8 |
10 |
20 |
| 1/2 |
15 |
23 |
| 3/4 |
20 |
55 |
| 1 |
25 |
95 |
| 11/4 |
32 |
155 |
| 11/2 |
40 |
260 |
| 2 |
50 |
440 |
| 21/2 |
65 |
710 |
| 3 |
80 |
1050 |
| 4 |
100 |
2040 |
Ball Valve Flow Table Size and Type / CV Flow Factors (US Gallons of water with pressure drop 1psi)
| SIZE / RATING | 150 | 300 | 600 | 900 | 1500 | 2500 |
|---|---|---|---|---|---|---|
| 1/2" | 19 | 19 | 19 | 18 | 16 | 18 |
| 3/4"x1/2" | 14 | 14 | 14 | 13 | 11 | 10 |
| 3/4" | 45 | 45 | 44 | 42 | 40 | 37 |
| 1"x3/4" | 29 | 29 | 28 | 28 | 27 | 21 |
| 1" | 87 | 96 | 84 | 82 | 77 | 57 |
| 1 1/2" x 1" | 51 | 51 | 45 | 48 | 48 | 31 |
| 1 1/2" | 220 | 246 | 225 | 205 | 199 | 154 |
| 2"x 1 1/2" | 121 | 134 | 142 | 133 | 133 | 105 |
| 2" | 432 | 464 | 431 | 361 | 344 | 305 |
| 3"x 2" | 195 | 201 | 224 | 226 | 181 | 211 |
| 3" | 1110 | 1113 | 1036 | 965 | 849 | 690 |
| 4"x 3" | 569 | 553 | 574 | 578 | 517 | 559 |
| 4" | 2063 | 2138 | 1947 | 1813 | 1645 | 1352 |
| 6"x 4" | 813 | 792 | 913 | 923 | 745 | 865 |
| 6" | 4743 | 5116 | 4635 | 4372 | 3874 | 2856 |
| 8"x 6" | 2340 | 2292 | 2316 | 2288 | 2082 | 1987 |
| 8" | 9706 | 9675 | 8786 | 8245 | 7444 | 5748 |
| 10"x 8" | 4606 | 4518 | 4472 | 4572 | 4256 | 4111 |
| 10" | 15771 | 15656 | 14287 | 13606 | 12002 | 9100 |
| 12"x 10" | 8832 | 8698 | 8661 | 7622 | 7931 | 7318 |
| 14"x 10" | 6225 | 6003 | 5972 | 5506 | 5711 | 5233 |
| 12" | 23671 | 23473 | 21851 | 20211 | 16807 | 13462 |
| 14"x 12" | 13972 | 14027 | 13944 | 13403 | 13364 | 12345 |
| 16"x 12" | 10744 | 10792 | 10882 | 10343 | 10405 | - |
| 14" | 28722 | 27979 | 26163 | 24100 | 22138 | - |
| 16"x 14" | 14844 | 14887 | 14715 | 14528 | 14169 | - |
| 16" | 38718 | 37887 | 35183 | 32862 | 29953 | - |
| 18"x 16" | 20721 | 20738 | 21102 | 20088 | 19447 | - |
| 20"x 16" | 17896 | 17982 | 18090 | 14305 | 13392 | - |
| 18" | 51656 | 50758 | 47378 | 43864 | 39666 | - |
| 20"x 18" | 28137 | 28209 | 28596 | 26977 | 24379 | - |
| 20" | 64558 | 62680 | 59133 | 56470 | 50894 | - |
| 24"x 20" | 27677 | 27680 | 27870 | 26400 | 24227 | - |
| 22" | 73062 | 71202 | 67357 | 51092 | 44930 | - |
| 24" | 97484 | 94720 | 93532 | 81286 | 71422 | - |
| 30"x 24" | 40532 | 40331 | 39867 | 38720 | 37130 | - |
| 26" | 106226 | 102087 | 97547 | 82605 | 71670 | - |
| 30"x 26" | 51377 | 51337 | 51238 | - | - | - |
| 28" | 127601 | 126158 | 118420 | 96770 | 84220 | - |
| 30" | 129337 | 121380 | 102799 | 112037 | 98390 | - |
| 36"x 30" | 70314 | 70006 | 70692 | 70095 | 65010 | - |
| 32" | 147306 | 144189 | 139906 | 129076 | 113800 | - |
| 36"x 32" | 87000 | 87000 | 87000 | 69500 | - | - |
| 34" | 183702 | 176536 | 164619 | 134485 | 129550 | - |
| 36" | 219178 | 211933 | 197055 | 167762 | 145950 | - |
| 42"x 36" | 96700 | 96700 | 96700 | - | - | - |
| 40" | 229927 | 229927 | 226344 | 248400 | - | - |
| 42" | 296175 | 296175 | 288550 | 275500 | - | - |
| 56"x 42" | 89000 | 89000 | 89000 | - | - | - |
| 44" | 351600 | 351600 | 331000 | 306400 | - | - |
| 48" | 398250 | 398250 | 388575 | 373200 | - | - |
| 56" | 563075 | 563075 | 554375 | - | - | - |