Distribution System Facilities Flashcards
What is friction loss?
a. A reverse flow condition created by a difference in water pressures that causes water to flow back into the distribution pipes of a potable water supply from any source or sources other than an intended source
b. The surface or profile of water flowing in an open channel or a pipe flowing partially full
c. The head, pressure, or energy lost by water flowing in a pipe or channel as a result of turbulence caused by the velocity of the flowing water and the roughness of the pipe, channel walls, or restrictions caused by fittings
d. The vertical distance equal to the pressure at a specific point
The head, pressure, or energy lost by water flowing in a pipe or channel as a result of turbulence caused by the velocity of the flowing water and the roughness of the pipe, channel walls, or restrictions caused by fittings
Why might a distribution system need to be oversized to meet fire demands?
a. To ensure that the system does not experience excessive pressure during a fire
b. A fire will draw water from the source very quickly
c. A fire can put very high demands on a system for short periods of time
d. To reduce the cost of pumping during a fire
A fire can put very high demands on a system for short periods of time
What determines whether transmission mains are short or long and whether the water is transported by gravity or pumping?
a. Location of the source
b. The materials used for transmission main construction
c. Treatment requirements to ensure safe water
d. Budget for the distribution system
Location of the source
Why should storage tanks be located in the center of use?
a. So that tanks do not interfere with views from houses and businesses
b. To provide larger capacities with fewer units
c. To reduce pumping costs
d. To maintain adequate pressures even during periods of high demand
To maintain adequate pressures even during periods of high demand
Why are storage pumps often installed in parallel?
a. To dewater the reservoir to allow for inspection and cleaning
b. To permit the economical location of storage at the desirable hydraulic elevation of the system
c. To enable the number of pumps in operation to be varied depending on the flow through the pumping station
d. To serve relatively few customers located on very high or remote points
To enable the number of pumps in operation to be varied depending on the flow through the pumping station
What is the first choice of methods to protect pipe from corrosion?
a. Proper use of noncorrosive metals and mechanical coatings
b. Chemical control methods
c. Cathodic protection
d. Vacuum, pressure-relief, and pressure-reducing valves
Proper use of noncorrosive metals and mechanical coatings
When installing water mains parallel to sanitary sewers, what is the recommended minimum horizontal separation between the two pipes?
a. 6 feet
b. 10 feet
c. 8 feet
d. 4 feet
10 feet
What is shoring?
a. An area near a body of water with a high groundwater table
b. A complete framework of wood or metal that is designed to support the walls of a trench
c. An area where surface water is readily visible and scenic
d. A wooden or metal wall placed on a trench
A complete framework of wood or metal that is designed to support the walls of a trench
When installing braces or screw jacks, which one should be installed first?
a. Right brace or jack
b. Bottom brace or jack
c. Top brace or jack
d. Left brace or jack
Top brace or jack
Which type of valve has a movable disc as large as the full diameter of the pipe?
a. Gate valve
b. Ball valve
c. Plug valve
d. Butterfly valve
Butterfly valve
Where are pressure relief valves most commonly installed?
a. On pipes 4 inches in diameter and smaller
b. On supply lines to elevated tanks or standpipes
c. At the high point of a line
d. On the side outlet of a tee at a specific point in the system
On the side outlet of a tee at a specific point in the system
How can a distribution system avoid putting large areas out of service for repairs or replacement?
a. Install valves in enough locations that relatively small parts of the system can be shut off
b. Only make repairs that can be completed while the line stays in service
c. Install backflow prevention devices in enough locations that relatively small parts of the system can be shut off
d. Install valves that can be operated by actuators
Install valves in enough locations that relatively small parts of the system can be shut off
Which fittings are used to change the direction of flow in a distribution system?
a. Caps, plugs, and blind flanges
b. Expansion joints, reducing flanges, and y-laterals
c. Clamps, sleeves, and adapters
d. Elbows, tees, and bends
Elbows, tees, and bends
One principal type of meter that will not interfere with the flow of water if the meter fails is the__________
Venturi meter
What is the main advantage of compound meters?
a. Their low head loss is ideal for a meter that must pass high rates of flow
b. They are less expensive than Venturi meters
c. They can measure wide variations of flow rate within their rated capacity
d. They accurately measure flows from a fraction of a gallon to the normal capacity of the pipeline
They accurately measure flows from a fraction of a gallon to the normal capacity of the pipeline
