Page 263 - Fair, Geyer, and Okun's Water and wastewater engineering : water supply and wastewater removal
P. 263
JWCL344_ch06_194-229.qxd 8/2/10 9:51 PM Page 223
Problems/Questions 223
4. Employers should ensure that fall protection equipment is appropriate and main-
tained in good condition. Employees should inspect fall protection equipment
before each use to ensure that all components are in operational order.
5. Employers should ensure that material hoists are not used for raising or lowering
employees to or from the worksite.
6. Employers should ensure that electrical safety practices are followed when welding.
7. Owners of water towers and similar structures should design and install a permanent
static safety line system on the tower to facilitate the use of fall protection devices.
PROBLEMS/QUESTIONS
6.1 An elevated water reservoir (water level at 210 m) is to
Pipe d (mm) L (m)
supply a lower groundwater reservoir (water level at 138 m).
The reservoirs are connected by 800 m of 400-mm ductile
AB 200 800
cast pipe (C 100) and 1,200 m of 300-mm ductile cast pipe
BC 200 200
(C 100) in series.
AD 200 200
(a) What will be the discharge delivered from the upper DC 300 800
reservoir to the lower one?
(b) If the water demand increases by 50% in the future, The elevation of point A is 600 m and of point B is 590 m. The
determine the required size of pipe that has to be in- C value for all pipes is 100. Find the following:
stalled in parallel with the existing piping.
(a) The length of a single 400-mm pipe that can replace
6.2 The following data are given for the water supply network the water network from A to C.
shown in Fig. 6.20:
(b) The residual pressure at point C, given that the flow
through the network is 250 L/s and the pressure at A
Pipe d (in.) L (ft) is 300 kPa.
AB 8 2,500 6.4 For the water supply network shown in Fig. 6.21, the fol-
BC 8 500 lowing data are given:
AD 8 500
DC 12 2,500 Pipe d (mm) L (m)
AB 300 1,200
The elevation of point A is 100 ft and of point B is 90 ft. The C
BD 300 300
value for all pipes is 100. Find the following:
AC 200 300
(a) The length of a single 18-in. pipe that can replace the CD 200 1,200
water network from A to C. SA d SA 10,000
(b) The residual pressure at point C, given that the flow
through the network is 4,000 gpm and the pressure at
Elevation 655 m
point A is 40 psi.
In A B
S
A B
D C
Out
Figure 6.20 Water Network for Problems 6.2 and 6.3 C D
60 L/s
6.3 The following data are given for the water supply network
shown in Fig. 6.20: Figure 6.21 Water Network for Problem 6.4