CHAPTER 7 WATER DISTRIBUTION SYSTEMS
Review Question Page References
(1) 184 (9) 190 (17) 194
(2) 184 (10) 190 (18) 194
(3) 185 (11) 192 (19) 194
(4) 184 (12) 193 (20) 198
(5) 185 (13) 196 (21) 201
(6) 186 (14) 196 (22) 202
(7) 187 (15) 196 (23) 203
(8) 189 (16) 194 (24) 203
(25) 205
(26) 204
(27) 206
(28) 207
(29) 209
(30) 209
(31) www.dipra.org/ductile.html
(32) www.envirosources.com
Solutions to Practice Problems
1. 52,500 people x 180 gal/person/d = 9,450,000 ≈ 9.5 mgd
4. F = 2 x P x A x sin(Δ/2): F = 2 x 600x(πx0.3052/4)xsin(90/2) = 62 kN
6. Tabulation for system head curve, using Fig. 2.15, with friction head loss hL = S x L
and TDH = hL + static head:
15
7. From Intersection of the pump curve (for parallel operation) and the system curve,
16
8. (continued)
9. Pout = Q x TDH/3960 (Eq. 7-7)
10. Pout = 9.8 x Q x TDH (Eq. 7-6)
II. Equalizing storage: 32,000 people x 500 L/d/person x 0.20 = 3.2 ML
.12. Pressure loss from the pump station to withdrawal point A is 100 kPa; the
13. Assume Q = 50 L/s; use the nomograph in Figure 2.15.
From Figure 2.15, with S = 0.005 and Q = 50 L/s, D = 260 mm
17
14. First establish an equivalent pipe for line ABC. Let Q = 30 L/s
hAB = 0.00027 x 1000 m = 0.27 m
15. First establish an equivalent pipe for the loop between B and C.
16. Pipe Dia., mm L, m Q, L/s S hLhL/Q
AB 400 1000 300 0.017 17 0.057
17. hAC = 59m and ΔP = 9.8 x h = 9.8 x 59 = 578 kPa
18. Pipe Dia., mm L, m Q, L/s S hL hL/Q
Loop I/Trial I
50
Δ
Q = -(-1.2/(1.85 x 0.19)) ≈ 3 L/s