Site Utilities and Plumbing Flashcards
Utilities are piped below ground up to _ feet from the building
5
If cast iron fittings are used, they must be _ lined
cement-mortar
Fire hydrants will be _, depending on freezing conditions, and installed with _.
wet or dry barrel, protective posts
Common materials include cast iron soil pipe, clay, concrete, or plastic up to _ inches in diameter.
15
Manholes are installed in sewer and drain piping to permit _ of the pipes.
inspection and maintenance
Straight runs of pipe will have manholes about _ feet apart.
500
Manholes more than _ feet deep will include a permanent ladder and be eccentric in shape.
12
Storm drain piping will carry only surface run-off water and underground seepage water by means of _.
gravity flow
A single conductor, #_ AWG (American Wire
Gauge) wire with type TW insulation, is installed alongside plastic pipe to aid in locating the gas pipe.
14
Gas steel pipe will be _ except at control valves, and coated as specified at the factory.
welded
Gas pipe joints are coated in the field with _.
factory supplied materials
Plastic pipe must be below ground, _ pounds per square inch gauge (psig) or less, and restricted to temperatures as specified in the contract.
100
Excavated material must be at least _ feet away from the edge of the trench.
2
Trenching more than _ feet deep may require bracing support, depending on the type of soil and
amount of moisture.
5
Ladders are required in trenches over _ feet deep, within _ feet of workers, and must extend _ feet above the ground surface.
4, 25, 3
The trench bed width is limited by specifications and extends from the bottom of the trench to _ foot above the pipe.
1
Depressions called _ must be dug in the trench bottom to accommodate the _ of the pipe and to provide space for making the joint.
bell holes, bell joints
The backfill material is specified by the contract. It gives the maximum rock size permitted, thickness
of each layer, compaction density, and _.
moisture content
Bell ends must face _hill.
up
Water lines must be _ feet horizontally from sewage lines, or at least _ feet if the water pipe is _ foot above the sewage line.
10, 6, 1
Thrust blocks or tie rods are required at all bends of _ degrees or greater and at all caps, plugs, tees, and fire hydrants.
22-½
Concrete thrust blocks should harden _ days prior to applying water pressure.
5
Sewer lines that cross over water lines should be encased in _ inches of concrete for _ feet on each side of the water line.
4, 10
Force mains must always cross _ feet beneath water lines.
2
There are three methods of testing for leakage in sanitary sewer lines: ,,_.
exfiltration, infiltration,
and the air test
When the trench has been backfilled to at least the _ (midpoint) of the pipe and the joints are still exposed, the pipe line must be tested for leakage by _.
spring line, exfiltration
Each pipe section between manholes is then tested by _ it at the lower end. The pipe is then filled with water and a _-foot head imposed on the upper end.
plugging, 2
The amount of water required to maintain it’s head during a _-hour period is measured.
2
The leakage must not exceed _ gallons per inch diameter, per _ feet of pipe, per hour.
0.2, 100
If the water table is above the top of the pipe, then the pipe must be tested by _.
infiltration
The Infiltration method measures for leakage by a _ (or dam) at the lower end.
V-notch weir
The third method used to test for sanitary sewer leakage, but one that is seldom used in Corps contracts, is a _ of vitrified clay pipe line (3 to _ inches).
low-pressure air test, 18
The sewer section is plugged at each end and pressurized with air to _ pounds per square inch gauge (psig) and the time noted for the pressure to drop to _ psig.
3.5, 2.5
This method can be used to locate a leak quickly and accurately by moving a pair of _ through the pipe and pressurizing the section between the _.
inflatable plugs, plugs.
A _ test is conducted when the trench has been backfilled _ feet above the top of the sewer pipe.
Displacement, 2
Each section between manholes is examined by _ into one end and observing the straightness of the pipe from the other end.
shining a light
Flexible sewer pipe, such as single-wall plastic, is inspected for _ after the trench is completely backfilled.
deflection
A plug of hard material having a diameter of _% of the actual inside diameter of the pipe is pulled through the
sewer section from one manhole to the other.
95%
If the plug will not pass freely through the pipe, then the sewer section is not satisfactory because the overburden has deformed the pipe more than _% of its diameter
5%
When watertight joints are required, a test is performed on each type of joint in the system before the pipe is installed. Two lengths of pipe are joined, and the joint is subjected to _
psi (pounds per square inch) hydro-static pressure for _ hours.
10, 24
The contractor is required to apply a pressure test and a leakage test to the water piping, usually at _ psi or _ times the working pressure.
- one-and-a-half
n the pressure test, the water pressure is held for _ hour(s), and the exposed joints and
piping are examined for leaks.
1
In the leakage test, the pressure is held for _ hour(s) and the leakage is measured by
recording the amount of water added to the system to maintain the pressure.
2
Pipe made of concrete or asbestos cement, or which is cement-lined or has mortar joints, should be filled with water _ before the test to permit these materials to absorb water.
several hours
The hydro-static pressure test for water piping that supplies fire protection systems must be at least _ psi and _ psi in excess of the maximum static pressure.
200, 50
Fire hydrants must be tested as specified in _.
NFPA 24
Natural gas system mains and service lines must be tested with air at _ psi or _% of the operating pressure, whichever is greater.
75 psi, 150%
Natural gas tests must continue for at least _ hours between the times of initial and final readings of temperature and pressure.
24
The sterilizing dosage of chlorine must be at least _ parts per million (ppm).
50
Chlorine compounds must be _ in water
before they are fed into plastic pipelines.
Dissolved
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