What is the minimum pressure required in the distribution system?
20 psi
The distribution system must have a minimum of _mg/L in the distribution mains.
0.2 mg/L
What is the minimum combined residual for the distribution system?
0.6 mg/L
What is the maximum free or combined chlorine residual in the distribution system?
4 mg/L
Valves on distribution mains should be how far apart?
800-1,000
How far apart are fire hydrants in residential areas?
500'
Fire hydrants in commercial areas should be how far apart?
No more than 300' from any part of a commercial building
How often should water main valves be exercised?
At least once a year
What is the main purpose of water storage tanks?
What is the configuration of a standpipe?
It is taller than it is wide
How many feet apart should a ladder be in a trench?
No more than 25' from any worker
How many ladders will you need for a 100' trench?
2 (25' from each end)
How far out of the trench should the ladder extend?
30"
When belled pipe is being installed, the bells are usually pointed in the direction that the work is heading except when the pipe is headed downhill, then the bell should?
Face uphill
How many feet from trench should the spoil bank be placed?
Minimum of 2 ft.
Excavations five feet or deeper must be?
Shored
Before doing any excavation work, you must?
Call for/Get Underground Locations
Any excavation or tank four feet or deeper is considered?
A Confined Space
Barricades with diagonal stripes must have the stripes?
Sloped toward traffic
When a pipeline changes direction or sizes, at dead ends, and when valves or hydrants are closed rapidly ______ must be installed?
Thrust Blocks
Water mains should be installed at least ______ horizontally from sewer mains.
10'
Water mains should be installed at least ______ higher than a sanitary sewer pipe.
1'
Surge Tanks are used to control?
Water Hammer
Where are air relief valves located in a distribution system?
At High Points
Hydropneumatic tanks should be equipped with?
Relief Valves
What type of valve is located at a point that is below the hydraulic gradient?
Altitude Valve
When should storage tanks be taken out of service for maintenance?
During periods of low demand
How do you disinfect the interior of a storage facility?
Spray or brush interior with a 200-PPM Cl₂ Solution
What is the minimum chlorine dosage to disinfect a newly installed main?
25 mg/L for 24 hours
The most commonly used joints on installed pipes are?
Push on joints
When should fire hydrants be inspected and serviced?
Twice a year
Where is the operating valve located in a dry barrel fire hydrant?
At the bottom
Distribution mains should be installed in a ог design to avoid dead ends?
Grid or Looped System:
What is a wet tap?
Installation/tap made under pressure
When a pipeline has been installed, the first layer of backfill is compacted to which point?
Up to the horizontal centerline of the pipe
A newly installed main is tested at a pressure higher than expected operating pressure or ________ psi for 24 hours?
50%, 250 PSI
What is measured after the completion of the pressure test?
Water loss or leakage
What is the chief purpose for of storage tanks?
To meet peak hourly demand