The coefficient of flow or Cv Value is the number of US gallons of water the valve will pass with a differential pressure of 1psi through the valve at 60F.

Kv is the metric value of Cv and is calculated as Kv=Cv x 0.85.

 Cv varies with both style and size of valve, but provides an index for comparing liquid capacities of different valves under a standard set of conditions. Table below provides Cv values of fully opened ball valves and are approximate values. The ball valve suppliers shall be consulted for getting the actual applicable values.

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"x1" 51 51 45 48 48 31
1 1/2" 220 246 225 205 199 154
2"x1 1/2" 121 134 142 133 133 105
2" 432 464 431 361 344 305
3"x2" 195 201 224 226 181 211
3" 1110 1113 1036 965 849 690
4"x3" 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"x6" 2340 2292 2316 2288 2082 1987
8" 9706 9675 8786 8245 7444 5748
10"x8" 4606 4518 4472 4572 4256 4111
10" 15771 15656 14287 13606 12002 9100
12"x10" 8832 8698 8661 7622 7931 7318
14"x10" 6225 6003 5972 5506 5711 5233
12" 23671 23473 21851 20211 16807 13462
14"x12" 13972 14027 13944 13403 13364 12345
16"x12" 10744 10792 10882 10343 10405 -
14" 28722 27979 26163 24100 22138 -
16"x14" 14844 14887 14715 14528 14169 -
16" 38718 37887 35183 32862 29953 -
18"x16" 20721 20738 21102 20088 19447 -
20"x16" 17896 17982 18090 14305 13392 -
18" 51656 50758 47378 43864 39666 -
20"x18" 28137 28209 28596 26977 24379 -
20" 64558 62680 59133 56470 50894 -
24"x20" 27677 27680 27870 26400 24227 -
22" 73062 71202 67357 51092 44930 -
24" 97484 94720 93532 81286 71422 -
30"x24" 40532 40331 39867 38720 37130 -
26" 106226 102087 97547 82605 71670 -
30"x26" 51377 51337 51238 - - -
28" 127601 126158 118420 96770 84220 -
30" 129337 121380 102799 112037 98390 -
36"x30" 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"x36" 96700 96700 96700 - - -
40" 229927 229927 226344 248400 - -
42" 296175 296175 288550 275500 - -
56"x42" 89000 89000 89000 - - -
44" 351600 351600 331000 306400 - -
48" 398250 398250 388575 373200 - -
56" 563075 563075 554375 - - -