Distribution
Name 4 types of water main material.
C900
Cast
Ductile
AC
Where must man holes be located?
Change of direction & elevation.
What is happening if you enter a pump station and it sounds like the pump is passing gravel?
Cavitation
What is the area of a trench that is 22.4 ft long and 3.3 ft wide?
74 sq ft
What of the following is the best anode?
a. brass
b. cast iron
c. zinc
d. copper
c. zinc
What is tensile strength?
Flexibility before breaking
Wet well vs dry well?
pump location
What type of valve is used to maintain prime on a pump?
foot
What is the area of the face of a 10in pipe?
0.54sq ft
What type of fire hydrant has no main valve but has separate valves for each nozzle?
Wet barrel
The size of water mains, pump stations, and tanks is primarily determined by what?
Fire protection
What happens if the flow in a collection system is
2 ft/sec or greater?
scouring
What type of valve is best to use to maintain the water level in a tank?
Altitude
A meter indicates water is flowing from a hydrant at 2.6 cfm. How many gallons will flow from the hydrant if it is flushed for 35 minutes?
682.5 gal
What is the byproduct of chlorine?
trihalomethanes
TTHMs
What is the min flushing velocity for unidirectional flushing?
5ft/sec
Odors in a basin would indicate that the sewage has become what?
Anaerobic
Why should isolation valves be installed at frequent intervals in the distribution system?
Small sections can be isolated.
What is the psi at the bottom of a 40 ft tank if the water level is 38.29 ft?
16.6 psi
What is the maximum theoretical suction at sea level of a centrifugal pump?
34ft
Define backflow vs backsiphonage.
Backsiphonage: reversal of normal water flow in a system caused by a negative pressure, or vacuum, in the supply piping.
Backflow: reverse flow of water or other substances into the drinking water distribution system.
An invert is best defined as?
lowest point in channel
What type of pump has rotating impellers within a pump case?
a. Axial-flow
b. Centrifugal
c. Jet
d. Mixed-flow
b. Centrifugal
A solution was found to be 63% calcium hypochlorite. What is the milligram per liter of calcium hypochlorite in the solution?
635,000 mg/L
What does SCADA stand for?
Supervisory Control and Data Acquisition