Water and Wastewater Engineering - Sciences Club

C-7
TABLE C-5 (continued)
Hydraulic headlosses for appurtenances
Appurtenance—
alphabetically
Headloss as
multiple of (v 2 /2g)
13. Orifice meters (in terms of velocities of
pipe) Orifice to pipe diameter ratio
0.25 (1:4) 4.8
0.33 (1:3) 2.5
0.50 (1:2) 1.0
0.67 (2:3) 0.4
0.75 (3:4)
14. Outlet losses
0.24
Bell mouthed outlet
⎛ v 2
1 v 2
2 ⎞
01 . �
⎝
⎜ 2g 2g
⎠
⎟
Sharp cornered outlet
⎛ v 2
1 v 2
2 ⎞
�
⎝
⎜ 2g 2g⎠
⎟
Pipe into still water or air
(free discharge)
15. Plug globe or stop valve
1.0
Fully open 4.0
¾ open 4.6
½ open 6.4
¼ open
16. Reducers
780.0
Ordinary (in terms of velocities of small
end)
0.25
Bell mouthed 0.10
Standard 0.04
Bushing or coupling
17. Return bend (2 nos. 90�)
0.05–2.0
Flanged—regular 0.38
Flanged—long radius 0.25
Screwed 2.2
Appurtenance—
alphabetically
eadloss as
multiple of (v 2 /2g)
18. Sluice gates
Contraction in conduit 0.5
Same as condult width without top submergence 0.2
Submerged port in 12 inch wall 0.8
19. Tees
Standard—bifurcating 1.5–1.8
Standard—90� turn 1.80
Standard—run of tee 0.60
Reducing—run of tee
2:1 (based on velocities 0.90
4:1 of smaller end) 0.75
20. Venturl meters
The headloss occurs mostly in and downstream
of throat, but losses shown are given in terms of
velocities at inlet ends to assist in design.
Long tube type—throat-to-inlet diameter ratio
0.33 (1:3) 1.0–1.2
0.50 (1:2) 0.44–0.52
0.67 (2:3) 0.25–0.30
0.75 (3:4) 0.20–0.23
Short tube type—throat-to-inlet diameter ratio
0.33 (1:3) 2.43
0.50 (1:2) 0.72
0.67 (2:3) 0.32
0.75 (3:4) 0.24
Source: A. Amirtharajah (1978) “Design of Granular Media Filter Units,” in R. L. Sanks (Ed.), Water Treatment Plant Design, Ann Arbor Science, Ann Arbor,
Michigan, PP. 702–704.