Fitting Loss Coefficients
For similar fittings, the K-value is highly dependent on things such as bend radius and contraction ratios.
Typical Fitting K Coefficients | |||
Fitting | K Value | Fitting | K Value |
Pipe Entrance | 90° Smooth Bend | ||
Bellmouth | 0.03-0.05 | Bend Radius / D = 4 | 0.16-0.18 |
Rounded | 0.12-0.25 | Bend Radius / D = 2 | 0.19-0.25 |
Sharp-Edged | 0.50 | Bend Radius / D = 1 | 0.35-0.40 |
Projecting | 0.80 | Mitered Bend | |
Contraction-Sudden | θ = 15° | 0.05 | |
D 2 /D 1 = 0.80 | 0.18 | θ = 30° | 0.10 |
D 2 /D 1 = 0.50 | 0.37 | θ = 45° | 0.20 |
D 2 /D 1 = 0.20 | 0.49 | θ = 60° | 0.35 |
Contraction-Conical | θ = 90° | 0.80 | |
D 2 /D 1 = 0.80 | 0.05 | Tee | |
D 2 /D 1 = 0.50 | 0.07 | Line Flow | 0.30-0.40 |
D 2 /D 1 = 0.20 | 0.08 | Branch Flow | 0.75-1.80 |
Expansion-Sudden | Cross | ||
D 2 /D 1 = 0.80 | 0.16 | Line Flow | 0.50 |
D 2 /D 1 = 0.50 | 0.57 | Branch Flow | 0.75 |
D 2 /D 1 = 0.20 | 0.92 | 45° Wye | |
Expansion-Conical | Line Flow | 0.30 | |
D 2 /D 1 = 0.80 | 0.03 | Branch Flow | 0.50 |
D 2 /D 1 = 0.50 | 0.08 | ||
D 2 /D 1 = 0.20 | 0.13 |