Owner manual
Resilient Seated Butterfly Valves – Valve Sizing Coefficients
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
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 : 17
Series 20/21 - Valve Sizing Coefficient (Kv)
Valve
Size
mm
Disc Position (Degrees)
10º 20º 30º 40º 50º 60º 70º 80º 90º
25 0.087 0.865 2.595 5.190 9.515 18.165 31.140 48.440 52.765
40 0.173 1.730 5.190 9.515 22.490 43.250 75.255 111.585 127.155
50 0.779 6.055 13.840 23.355 38.925 63.145 106.395 148.780 211.060
65 0.865 9.515 21.625 37.195 61.415 99.475 173.865 268.150 379.735
80 1.730 13.840 30.275 53.630 88.230 142.725 250.850 422.120 597.715
100 3.460 24.220 54.495 95.150 157.430 254.310 445.475 783.690 1,108.930
125 5.190 38.060 84.770 148.780 245.660 397.035 696.325 1,224.840 1,790.550
150 6.055 51.035 112.450 196.355 325.240 525.055 921.225 1,620.145 2,409.890
200 11.245 91.690 211.060 369.355 617.610 992.155 1,673.775 2,942.730 4,490.215
250 18.165 145.320 334.755 583.875 977.450 1,569.975 2,648.630 4,658.025 7,125.870
300 26.815 211.925 486.130 848.565 1,420.330 2,280.140 3,847.520 6,764.300 10,468.230
350 34.600 265.555 610.690 1,067.410 1,785.360 2,865.745 4,835.350 8,502.085 13,156.650
400 44.980 348.595 800.125 1,398.705 2,340.690 3,756.695 6,338.720 11,145.525 17,248.100
450 58.820 456.720 1,049.245 1,834.665 3,069.885 4,926.175 8,312.650 14,616.770 22,619.750
500 73.525 570.900 1,312.205 2,293.115 3,837.140 6,158.800 10,392.110 18,272.260 28,276.850
Series 22/23 - Valve Sizing Coefficient (Kv)
Valve
Size
mm
Disc Position (Degrees)
10º 20º 30º 40º 50º 60º 70º 80º 90º
50 0.865 6.055 13.840 23.355 38.060 53.630 73.525 99.475 126.290
65 0.865 9.515 20.760 37.195 59.685 95.150 152.240 203.275 259.500
80 1.730 12.975 30.275 52.765 84.770 136.670 247.390 357.245 506.890
100 2.595 23.355 53.630 94.285 153.105 246.525 435.095 702.380 909.115
125 4.325 37.195 84.770 147.915 238.740 380.600 690.270 1,121.905 1,569.110
150 5.190 49.305 111.585 195.490 314.860 501.700 906.520 1,502.505 2,228.240
200 10.380 89.960 209.330 366.760 603.770 961.015 1,650.420 2,717.830 3,766.210
250 17.300 142.725 333.025 581.280 955.825 1,523.265 2,598.460 4,304.240 5,911.410
300 25.085 208.465 483.535 843.375 1,387.460 2,241.215 3,823.300 6,394.080 8,727.850
350 30.275 259.500 622.800 1,107.200 1,816.500 2,854.500 4,930.500 8,087.750 11,141.200
400 38.925 302.750 735.250 1,427.250 2,378.750 3,806.000 6,487.500 10,656.800 14,618.500
450 47.575 441.150 1,038.000 1,816.500 3,114.000 4,930.500 8,502.950 13,494.000 18,684.000
500 69.200 562.250 1,340.750 2,335.500 3,875.200 6,141.500 10,553.000 17,213.500 23,787.500
600 155.700 865.000 2,119.250 3,979.000 6,055.000 9,774.500 16,348.500 24,652.500 30,102.000