Duct fitting pressure drop coefficients for
round butterfly damper
From ASHRAE (1989), with permission
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Values of C0
q, deg | ||||||||||||
0 |
10 |
20 |
30 |
40 |
50 |
60 |
70 |
75 |
80 |
85 |
||
D / D0 |
0.5 |
0.19 |
0.27 |
0.37 |
0.49 |
0.61 |
0.74 |
0.86 |
0.96 |
0.99 |
1.0 |
1.0 |
0.6 |
0.19 |
0.32 |
0.48 |
0.69 |
0.94 |
1.2 |
1.5 |
1.7 |
1.8 |
1.9 |
1.9 |
|
0.7 |
0.19 |
0.37 |
0.64 |
1.0 |
1.5 |
2.1 |
2.8 |
3.5 |
3.7 |
3.9 |
4.1 |
|
0.8 |
0.19 |
0.45 |
0.87 |
1.6 |
2.6 |
4.1 |
6.1 |
8.4 |
9.4 |
10 |
10 |
|
0.9 |
0.19 |
0.54 |
1.2 |
2.5 |
5.0 |
9.6 |
17 |
30 |
38 |
45 |
50 |
|
1.0 |
0.19 |
0.67 |
1.8 |
4.4 |
11 |
32 |
113 |
- |
- |
- |
- |