1. Week 2: Water Conveyance
EAT 237
WATER SUPPLY ENGINEERING
Week 2:
Water Conveyance
Fahmi Muhammad Ridwan
SCHOOL OF ENVIRONMENTAL ENGINEERING
UNIVERSITI MALAYSIA PERLIS
2017

2. Water Conveyance system
Objective : To provide a conduit to pump water from the raw water intake to the treatment plant and from the treatment plant to the point of use.
Types of Conveyance System
Open Channels: Canals, Flumes and Aqueducts, Gravity Conduits, Grade Tunnels
Pressure Conduit

3. Hydraulics Considerations
For Open Channel: Manning Equation
For Pressure Conduits: Hazen-Williams Equation
In U.S customary Unit:

4. The coefficient Ch is dependent only on the condition of the surface of the pipe or conduit. Table 8.3 gives typical values Ch
Average for
New, Clean Pipe
Design
Value
Type of Pipe

5. The Hazen–Williams formula for SI units is

6. Other types of calculations that are often desired are:
To determine the required size of pipe to carry a given flow rate while limiting the energy loss to some specified value.
To determine the energy loss for a given flow rate through a given type and size of pipe of a known length.
The following table shows several forms of the Hazen–Williams formula that facilitate such calculations.

8. Nomograph for solving the Hazen-Williams Formula
The nomograph shown in the following figure allows the solution of the Hazen–Williams formula to be done by simply aligning known quantities with a straight edge and reading the desired unknowns at the intersection of the straight edge with the appropriate vertical axis.
Note that this nomograph is constructed for the value of the Hazen–Williams coefficient of Ch = 100.

10. Example 1
For what velocity of flow of water in a new, clean, 6-in Schedule 40 steel pipe would an energy loss of 6.1 m of head occur over a length of m? Compute the volume flow rate at that velocity. Then refigure the velocity using the design value of Ch for steel pipe.
Example 2
Specify the required size of Schedule 40 steel pipe to carry m3/s of water with no more than 4.0 m of head loss over a 1000 m length of pipe. Use the design value for Ch.

11. Tutorial Question 1 Tutorial Question 2 Tutorial Question 3
Water flows at a rate of m3/s through m of 6-in cement line ductile iron pipe. Compute the energy loss
Tutorial Question 2
Compute the energy loss as water flows in a 4-in type K copper tube at a rate of 1000 L/min over a length of 45 m.
Tutorial Question 3
A fire protection system includes m of 10-in schedule 40 steel pipe. Compute the energy loss in the pipe when it carries L/min of water
Tutorial Question 4
A 4-in type K copper tube carries 900 L/min of water over length of 80 m. Compute the energy loss.

12. Tutorial Question 5 Tutorial Question 6 Tutorial Question 7
Specify the suitable size of new, clean schedule 40 steel pipe that would carry L/min of water over a length of m with no more than 3.05 m of head loss. For the selected pipe, compute the actual expected head loss.
Tutorial Question 6
For the pipe selected in Question 5, compute the head loss using the design value for Ch rather than that for new, clean pipe.
Tutorial Question 7
Compute the head loss that would result from the flow of L/min of water through m of new, clean schedule 40 steel pipe for 2-in and 3-in sizes.