Distribution operator Flashcards
Regardless of staging, the maximum theoretical suction lift of any pump is about:
34 ft.
To properly flush a newly installed water main, the MINIMUM velocity should be:
2.5 ft. per sec.
The two basic categories of pumps used in water supply are:
Velocity
Positive displacement
Minimum pressure in a distribution system should not fall below:
20 psi
The pH scale extends from:
0-14
What is the weight of 1 cubic foot of water?
- 4 Lbs.
8. 34 X 7.48
Fire demand can account for as much as ____% of the total storage capacity.
50%
Amount of storage and size of distribution mains is usually determined by:
Fire-flow demand
Sheeting and shoring must be used in any excavation that is:
5 ft. or more in depth
Class A fire extinguisher would be used on:
Paper, wood and clothing.
In a dry barrel fire hydrant, the main valve is located:
In the foot
Material excavated from a trench must be placed ___ft. from trench?
2 ft.
Chlorine gas is:
Greenish-yellow in color.
Flanged joint fittings are mainly used for:
Above ground fittings
Most common type of meter used for private homes is:
Displacement
What form of chlorine is most commonly used to disinfect a new water main?
Calcium hypochlorite
Type of meter usually accurate over a wide range of flow is:
Compound
Electrical current flow is measured in:
Amps
The minimum distance a potable water line should be laid from a sewer line is:
10 ft.
How often should an RPZ backflow preventer be tested?
Once a year
C-factor refers to:
The smoothness of the interior of the pipe.
Piezo metric elevation or pressure head is:
Vertical water column height
What is the advantage in using centrifugal pumps?
Easy to repair
When sampling for bacteria, sample bottle is prepared with which chemical in bottle?
Sodium Thiosulfate
What is the main purpose of a water storage facility?
Provide sufficient amount of water to average or equalize the daily demands plus provide minimum pressures to fight fires
Electrical demand in a wiring system is determined by the amount of:
Watts consumed
Baffling in a storage facility is needed to prevent:
Straight through flows
Chlorine may be added to water in continuous, slug and/or the _____ method.
Tablet
Eighty parts per billion is equal to:
0.08mg / l
What is the main difference between surface and groundwater contamination?
Groundwater takes longer to recover after contamination.
What constitutes a cross-connection?
A connection between an approved and an unapproved water supply.
What type of meter is used when the water flow widely fluctuates?
Compound meter
Distribution systems are laid out in the following patterns.
Loops and/or circular designs
Dead ends in a system are usually located on:
Tree shaped and grid designs
Electrical system for prevention of rust and corrosion and pitting is called:
Cathodic protection
Most common type of pipe joint is:
push-on joint
Absolute minimum pressure a water system should maintain at all times is:
20 psi
Systematic destruction of disease producing organisms is:
disinfection
Group of bacteria found in intestines of warm blooded animals:
Coliform
The principal purpose of an altitude valve on an elevated tank is to:
Control maximum filling level in distribution storage.
Cathodic protection systems for tanks use sacrificial anodes and:
A direct current power supply.
The rotating element in centrifugal pumps is commonly called an
Impeller
The pressure exerted by a column of water when at rest is the ___________ pressure.
Static
What is the primary purpose of well grouting?
Prevent surface water contamination from entering the aquifer.
The type of corrosion caused by the use of dissimilar metals in water systems is known as ______corrosion.
Galvanic
The term for the pressure against which a pump must operate is:
Head
What do most pumps require before they can pump fluids?
The casing is full of water (Primed).
A pipe’s carrying capacity depends on its size, water pressure, flow velocity and what other factor?
Head loss
What is pressure head caused by?
Water elevation.
What is the maximum recommended distance between valves on mains 12 inch and smaller?
1000 feet
Where should distribution storage tanks be located in the system?
In the center of the system.
Fire demand can account for what percent of flow in the design of a water system.
50%
Complaints of poor water quality most likely occur in: A. Arterial loop B. Grid C. Tree D. Nebular
C. Tree
Asbestos-cement pipe contains which of the following materials? A. Fiberglass B. Silica sand C. Polyethylene D. Crushed granite
B. Silica Sand
What type of joint should not be used in underground applications? A. Mechanical B. Flange C. Ball D. Flare
B. Flange
