Civil Engineering Reference
In-Depth Information
TABLE 26-3. Special Losses of Head (
K
L
) in Terms of
V
2
/2
g
Losses in Pipes, Pipe Fittings, and Valves
Appurtenance, Alphabetically
K
L
BENDS
90
Elbow
Flanged, regular
Flanged, long radius
Smooth-Rough
0.21-0.30
0.14-0.23
90
Bend
Screwed, short radius
Screwed, midum radius
Screwed, long radius elbow
.9
.75
.60
Intersection of two cylinders
(not rounded, e.g., welded pipe)
1.25-1.8
45
Elbow
Screwed, regular
Flanged, long radius
Flanged, regular
General rule to use
0.30-0.42
0.18-0.20
0.20-0.30
3
⁄
4
of loss for 90
bend of
same radius
22
1
⁄
2
Bend
Use
1
⁄
2
of loss for 90
bend of same radius
Standard 45
bend (4-18
)
0.20-0.30
Obtuse-Angled
Deflection of pipe (
)
90
2
1.5
90
Return Bend
Flanged, regular
Flanged, long radius
Screwed, regular
0.38
0.25
2.2
Any Bend
(
except as above
)
angle of bend
0.25
90
Wye Branches or 45
Laterals
Use
3
⁄
4
of the loss for a tee, or
1.0
Te e
Standard, bifurcating
Standard, 90
turn
Standard, run of tee
Reducing, run of tee of
1
⁄
2
Reducing, run of tee of
1
⁄
4
Use losses for 90
bend with zero radius
1.50-1.80
1.80
0.60
0.90
0.75
