LANDSCAPING CONTRACTOR: TEST 1
QUESTIONS WITH DETAILED VERIFIED
ANSWERS
What is the least effective backflow preventer a city may use to protect
the water supply? Ans: AVB
If a backflow preventer is lower than the highest sprinkler head, what
kind should you use to protect a city's water supply? Ans: Reduced
pressure.
Which of the following is used in drainage? Ans: C. B.
Which is not a nominal size of drainage pipe? Ans: 5''
If an automatic sprinkler system won't turn off, the most likely cause is:
Ans: Faulty solenoid.
Why do you need to know the elevation of sprinkler pipes? Ans: To
calculate pressure loss.
Which of these sprinkler heads throws the most water? Ans: Impact-
drive rotary.
What is the most expensive type of 3/4'' PVC pipe? Ans: Schedule 80.
According to code, what is the size of the drain PLATE running from a
catch basin? Ans: 4''
According to code, what is the size of the drain LINE running from a catch
basin? Ans: 4''
The minimum coverage for underground installation of main line PVC is
______ below finish grade. Ans: 12''
, Page | 2
What is the main reason galvanized pipe or gray [brownline] PVC could
be run along the surface of the ground but not white PVC? Ans: White
PVC will become brittle in sunlight.
If one sprinkler head is 20 ft higher than another, what change in the psi
would you expect when going from the upper to the lower head? Ans:
+8.66 psi
If you put a pump on a water system to increase pressure, where does
the atmospheric vacuum beaker go? Ans: Between the pump and the
system.
What is the typical size of a water meter connection for a suburban city
lot? Ans: 3/4
If a sprinkler head is misting rather than spraying, what is the most likely
cause of the problem? Ans: Too much pressure.
If the last head in a system continuously weeping, the most likely cause
is: Ans: A worn valve washer.
What is the most commonly used type of control valve? Ans: Diaphram.
The main valve that produces maximum flow when open is: Ans: Gate.
The symbol below shows a: Ans: Gate valve.
The symbol below shows a: Ans: Globe valve.
Low-precipitation heads are most useful when the landscaper is faced
with: Ans: Soil with slow water infiltration (low permeability) and low
water pressure (low GPM).
How long should you wait before applying static water pressure to newly
made PVC solvent weld? Ans: 24 hours.
After PVC main and lateral lines are installed and flushed, they should be
tested under constant pressure for: Ans: MAIN: 6 hours at 125 psi;
LATERAL: 2 hours at 100 psi