Bray 31U - Manual (Page 15)

Resilient Seated Butterfly Valves – Valve Sizing Coefficients
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The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Coefficients : 15
Series 20/21 - Valve Sizing Coefficient (Cv)
Valve
Size
inches
Disc Position (Degrees)
10º 20º 30º 40º 50º 60º 70º 80º 90º
1 0.1 1 3 6 11 21 36 56 61
1.5 0.2 2 6 11 26 50 87 129 147
2 0.9 7 16 27 45 73 123 172 244
2.5 1 11 25 43 71 115 201 310 439
3 2 16 35 62 102 165 290 488 691
4 4 28 63 110 182 294 515 906 1,282
5 6 44 98 172 284 459 805 1,416 2,070
6 7 59 130 227 376 607 1,065 1,873 2,786
8 13 106 244 427 714 1,147 1,935 3,402 5,191
10 21 168 387 675 1,130 1,815 3,062 5,385 8,238
12 31 245 562 981 1,642 2,636 4,448 7,820 12,102
14 40 307 706 1,234 2,064 3,313 5,590 9,829 15,210
16 52 403 925 1,617 2,706 4,343 7,328 12,885 19,940
18 68 528 1,213 2,121 3,549 5,695 9,610 16,898 26,150
20 85 660 1,517 2,651 4,436 7,120 12,014 21,124 32,690
Series 22/23 - Valve Sizing Coefficient (Cv)
Valve
Size
inches
Disc Position (Degrees)
10º 20º 30º 40º 50º 60º 70º 80º 90º
2 1 7 16 27 44 62 85 115 146
2.5 1 11 24 43 69 110 176 235 300
3 2 15 35 61 98 158 286 413 586
4 3 27 62 109 177 285 503 812 1,051
5 5 43 98 171 276 440 798 1,297 1,814
6 6 57 129 226 364 580 1,048 1,737 2,576
8 12 104 242 424 698 1,111 1,908 3,142 4,354
10 20 165 385 672 1,105 1,761 3,004 4,976 6,834
12 29 241 559 975 1,604 2,591 4,420 7,392 10,090
14 35 300 720 1,280 2,100 3,300 5,700 9,350 12,880
16 45 350 850 1,650 2,750 4,400 7,500 12,320 16,900
18 55 510 1,200 2,100 3,600 5,700 9,830 15,600 21,600
20 80 650 1,550 2,700 4,480 7,100 12,200 19,900 27,500
24 180 1,000 2,450 4,600 7,000 11,300 18,900 28,500 34,800