Duct fitting pressure drop coefficients for
elbow with smooth radius
From ASHRAE (1989), with permission
The pressure drop coefficient is given by C = Kq · C90
|
Coefficients for 90° elbows | Angle correction factors Kq |
||
r/D |
C90 |
q | Kq | |
0.5 |
0.71 |
0 |
0 |
|
0.75 |
0.33 |
20 |
0.31 |
|
1.0 |
0.22 |
30 |
0.45 |
|
1.5 |
0.15 |
45 |
0.60 |
|
2.0 |
0.13 |
60 |
0.78 |
|
2.5 |
0.12 |
75 |
0.90 |
|
90 |
1.00 |
|||
110 |
1.13 |
|||
130 |
1.20 |
|||
150 |
1.28 |
|||
180 |
1.40 |