Page 196 - Water Engineering Hydraulics, Distribution and Treatment

174
Water Hydraulics, Transmission, and Appurtenances
Chapter 5
(b) How many meters will the water level rise in the elevated reser-
is not to be less than 150 kPa.
(c) Find the residual pressure at point C if a different pump is used,
C
one that can deliver half the flow into the system at the same
L = 1,000 m
pumping head above.
A
G
B
D L = 1,200 m
L = 1,600 m
Ground
P
B
reservoir
L = 500 m
L = 500 m Elevated
F
E L = 1,000 m
A
Reservoir
C
Figure 5.35 Water system for Problem 5.11.
water level
P
Q c
at 100.00 m
In the water supply system shown in Fig. 5.36, the pumping
5.12 voir if valves E and F were opened? L = 1,000 m reservoir (b) Calculate the pumping head, if the residual pressure at point C
38 L/s
station (P) delivers the water from the water treatment plant (WTP) D
to city ABCDE. The water head delivered by the pumps is 28 m.
15 L/s
The water level in the pumping station wet well is at 600.00 m. The
value of C for all pipes is l00. Figure 5.37 Water system for Problem 5.13.
The following elevations are known:
5.14 Consider a vertical rectangular gate (b × h = 13.12 ft ×
A. 570.00 m.
6.56 ft = 4m × 2 m) that is vertically submerged in water so
B. 575.00 m. that the top of the gate is 13.12 ft (4 m) below the water surface.
C. 573.00 m. Determine the total resultant force on the gate and the location of
(a) Find the required diameter of the force main PA (d ), if the the center of pressure (see Fig. 5.6).
PA
pressure at point A is not allowed to drop below 370 kPa.
(b) Determine the required diameter of pipe BC (d ), if the max- 5.15 In Fig. 5.3 the areas of the plunger A and cylinder B are
BC
2
2
2
2
imum allowed head loss in the network ABC is 3‰. 6in. (38.71 cm ) and 600 in. (3,871 cm ), respectively, and the
weight of B is 9,000 lb (4,086 kg). The vessel and the connecting
(c) Calculate the actual residual pressures at points A and C.
passages are filled with oil of specific gravity 0.75. What force is
Pipe d (mm) Length (m) 40 L/s required for equilibrium, neglecting the weight of A and assuming
d = 16 ft (4.88 m).
PA d PA 3,000
AB 400 800 B
BC d BC 800 5.16 Gate EBC shown in Fig. 5.13 is hinged at B and is 4 ft
(1.22 m) wide. Neglecting the weight of the gate, determine the
AEDC 400 1,500
unbalanced moment due to water acting on the gate EBC. It is
◦
A assumed that = 60 , d = 8 ft (2.44 m), and a = 3 ft (0.91 m).
WTP P C
180 L/s
5.17 Oil of specific gravity 0.75 flows through the nozzle shown
55 L/s E D
in Fig. 5.1 and deflects the mercury (specific gravity 13.57) in the
Figure 5.36 Water system for Problem 5.12. U-tube gauge. Determine the value of h if the pressure at D is 20
2
psi (138.8 kN/m )and m is 2.75 ft (0.84 m).
5.13 In the water supply system shown in Fig. 5.37, water is
pumped from the ground reservoir to the vi1lage ABCD (elevation 5.18 The funnel shown in Fig. 5.38 is full with water. The volume
of 120.00 m) through the water main PA. The value of C for all of the upper part is 5.9 ft (0.1671 m ) and of the lower part is 2.6 ft 3
3
3
pipes is 100. A water meter located on pipe DC indicates a flow of
20 L/s. The following network data are provided:
Water surface A W
Pipe d (mm) L (m)
PA 500 10,000 a
AB 250 500
AC 200 700
AD 200 500
BC 250 1,000 b
CD 150 1,000
A C
(a) Determine the flow in each pipe as well as the flow delivered to
point C (Q ). Figure 5.38 Funnel for Problem 5.18.
c