Chapter 14 Water Supply Flashcards
Name the two types of water supply systems in North America.
Public and Private
Name four components of a water supply system.
Water supply source. Processing and treatment facility. Means of moving water. Water distribution and storage systems.
How many times more saltier is the ocean then fresh water?
220 times
Name three methods of moving water.
Gravity, Pumping, Combination
How high does the water source need to be above the highest use point in a gravity system?
100’
Most direct pumping systems are found in what two areas?
Industrial and agricultural.
In a direct pumping system, what is necessary to ensure a reliable system?
Duplicate pumps and piping.
Many industrial facilities have their own elevated storage tanks making this kind of system possible.
Combination system.
Name the four system components of a water distribution system.
Piping. Storage tanks. Isolation and control valves. Hydrants
Generally made of cast iron, ductile iron, asbestos cement, steel, PVC, plastic, or cement.
Underground water mains.
Name the three types of water mains found in a water distribution grid.
Primary Feeders. Secondary Feeders. Distrubutors
Also know as arterial mains. Range from 16” to 72”.
Primary Feeders
Interconnect with primary feeders to create a grid. 12” - 14” wide. Control Valves are used to isolate each of these.
Secondary Feeders
6” - 8” wide. Serve individual fire hydrants.
Distributors
T or F To ensure a sufficient water supply, two or more primary feeders should run from the source of supply to the high risk and industrial districts of the community along separate routes. Similarly, secondary feeders should provide water from the primary feeders along two directions to any end point.
True
Today, …..inch pipe is often the minimum size used, although some communities are allowing ……inch pipes in residential subdivisions.
8”, 6”
Elevated water storage tanks are usually constructed of what?
Concrete or steel.
What is the range of capacity for a elevated storage tank?
5000 to over a million gallons.
Most valves are constructed of what?
Brass, steel, or cast iron.
Name the two types of valves used in a water supply system.
Isolation and control valves.
Either gate valves or butterfly valves. Maximum length of valve spacing should be 500’ in high value districts and 800’ in other areas. Should be tested (opened and closed) at least once a year. Non-indicating type valves on municipal water supply systems. Private systems usually have indicating valves. Typically found on secondary feeders.
Isolation valves
Name the two most common indicating valves.
OS&Y and Post Indicator Valve (PIV)
What position is the OS&Y vale is you can see the stem?
Open
Name seven types of control valves.
Pressure reducing. Pressure sustaining. Pressure relief. Flow control. Throttling. Float. Check.
Located between public and private water supply systems.
Control Valves.
Two additional components that are installed between a public and private water supply system besides control valves.
Flow Meter. Back Flow Preventer
Fire hydrants are usually connect to the water system by what size pipe?
6”
Fire hydrants should not be spaced more then ……. in high value districts. Hydrants should be located at ………intersection. Additional hydrants may be needed where distances between intersections exceeds 350 to 400 feet.
300’, every other. (this place a hydrant within one block of a building).