Butterfly Valves
Cv value of Butterfly Valves
The valves Cv is the flow rate (in US gal/min) of pure water at 600F passing through
the valves when the valves disc is fully opened and the pressure differential between the two ends
of the valves is 1 Lbf/in 2
V. Max. Flow ( in us gal/min)
G: Specific gravity (1 for water)
P1: Inlet side pressure (Lbf/in 2)
P2:Outlet side pressure (Lbf/in2)
Cv = 1.17C
Conversion of flow resistance coefficient and Cv value
d:Valves bore size or valves seat bore size (in)
ζ
: Flow resistance coefficient (no unit)
| Size |
Flow in Gpm@ 1PSI P@ Various Disc Angles |
Full 90?open |
| inch |
DN |
10?/td>
| 20?/td>
| 30?/td>
| 40?/td>
| 50?/td>
| 60?/td>
| 70?/td>
| 80?/td>
|
| 2" |
50 |
0.1 |
5 |
12 |
24 |
45 |
64 |
90 |
125 |
135 |
| 2.5" |
65 |
0.2 |
8 |
20 |
37 |
65 |
98 |
144 |
204 |
220 |
| 3" |
80 |
0.3 |
12 |
22 |
39 |
70 |
116 |
183 |
275 |
302 |
| 4" |
100 |
0.5 |
17 |
36 |
78 |
139 |
230 |
364 |
546 |
600 |
| 5" |
125 |
0.8 |
29 |
61 |
133 |
237 |
392 |
620 |
930 |
1022 |
| 6" |
150 |
2 |
45 |
95 |
205 |
366 |
605 |
958 |
1437 |
1579 |
| 8" |
200 |
3 |
89 |
188 |
408 |
727 |
1202 |
1903 |
2854 |
3136 |
| 10" |
250 |
4 |
151 |
320 |
94 |
1237 |
2047 |
324 0 |
4859 |
5340 |
| 12" |
300 |
5 |
234 |
495 |
1072 |
1911 |
3162 |
5005 |
7507 |
8250 |
| 14" |
350 |
6 |
338 |
715 |
1549 |
2761 |
4568 |
7230 |
10844 |
11917 |
| 16" |
400 |
8 |
464 |
983 |
2130 |
3971 |
6282 |
9942 |
14913 |
16388 |
| 18" |
450 |
11 |
615 |
1302 |
2822 |
5028 |
8320 |
13168 |
19752 |
21705 |
| 20" |
500 |
14 |
791 |
1674 |
3628 |
6465 |
10698 |
16931 |
25396 |
27903 |
| 24" |
600 |
22 |
1222 |
2587 |
5606 |
9989 |
16538 |
26157 |
39236 |
43116 |
| 28" |
700 |
36 |
1813 |
3639 |
6636 |
10000 |
14949 |
22769 |
34898 |
49500 |
| 32" |
800 |
45 |
2387 |
4791 |
8736 |
13788 |
20613 |
31395 |
48117 |
68250 |
| 36" |
900 |
60 |
3021 |
3063 |
11055 |
17449 |
26086 |
39731 |
60895 |
86375 |
| 40" |
1000 |
84 |
4183 |
8395 |
15307 |
24159 |
36166 |
55084 |
84425 |
119750 |
|
