Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Irrigation Tech Practice Exam > Irrigation Tech Practice Exam > Flashcards

Irrigation Tech Practice Exam Flashcards

Backflow & Prevention

1
Q

___ has the authority to implement rules governing irrigation licenses.

A

A. Texas Turf Irrigation Association
B. Irrigator Advisory Board
C. Texas Commission on Environmental Quality.
D. Texas Engineering Extension Agency.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Number of Irrigation related licenses regulated by the TCEQ

A

A. 1
B. 2
C. 3
D. 4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When is it acceptable to exceed the manufacturers recommendations?

A

A. Never
B. when wind velocities are less than 5mph always
C. Always
D. when irrigating tight soils like clay.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the minimum amount of pipe coverage required?

A

A. Below the freeze level
B. 2”
C. 18”
D.16”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the minimum area required for spray emission devices to be used when bordered by hardscape?

A

A. there is not a minimum.
B. 12”
C. 24”
D. 48”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 4 items must be completed before an irrigation system is considered finished?

A
  1. __________
  2. __________
  3. __________
  4. __________
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Who can authorize changes to the irrigation plan?

A

A. Licensed Irrigator
B. Licensed Irrigation Technician
C. Both of these.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

A licensed irrigation technician can perform all of the work in the field as long as he is under the supervision of a licensed irrigator.

A

A. True

B. False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When can a licensed irrigation technician alter the head layout?

A

A. anytime
B. never
C. At the request of the system’s owner
D. after approval of the licensed irrigator.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Who can perform the system walk through with the system’s owner?

A

A. irrigator.
B. Technician.
C. both of these.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Backflow is caused by _____.

A

A. unprotected cross connections.
B. constant pressure
C. back pressure and back siphonage
D. velocities over 5 ft/sec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The air gap on a system supplied by a 2” supply pipe should be a minimum of _____.

A

A. 1”
B. 2”
C. 3”
D. 4”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

An atmospheric Vacuum Breaker is not suitable for ______.

A

A. installation after zone valves.
B. installation before zone valves.
C. preventing back siphonage
D. non-health Hazard applications.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which backflow prevention device has a spring loaded float and a check valve?

A

A. Atmospheric Vacuum Breaker
B. Pressure Vacuum Breaker
C. Double Check Valve Backflow Prevention Assembly
D. Reduced Pressure Principle Backflow Prevention Assembly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which Backflow prevention device is required for systems with fertilizer injectors?

A

A. Atmospheric Vacuum Breaker
B. Pressure Vacuum Breaker
C. Double Check Valve Backflow Prevention Assembly
D. Reduced Pressure Principle Backflow Prevention Assembly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which of the following can repair a faulty backflow prevention device?
I. Licensed Irrigator
II. Licensed Irrigation Technician
III. Licensed Backflow Prevention Assembly Tester.

A

A. I only.
B. I, II, and III.
C. I, III.
D. III only.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

For every foot of elevation gained or lost you will gain or lose ____ psi.

A

A. 0.866
B. 2.31
C. 1
D. 0.433

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

If the faucet in the back yard has a higher static pressure reading than the faucet in the front yard, then which statement is correct?

A

A. The property is level.
B. The property is sloped with the front yard being higher than the back yard.
C. The property is sloped with the back yard being higher than the front yard.
D. The faucets are not suitable for drinking.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

1 psi = ____ft/hd?

A

A. 0.433
B. 1
C. 2.31
D. 0.866

20
Q

if the water tower has a column of water 231’ tall is the pressure at the bottom?

A

A. 231 psi
B. 533 psi
C. 100 psi
D. 43.3 psi

21
Q

The static pressure reading taken at the water meter reads 50 psi. If the closest faucet is 30 yards away and- 21’ above the meter, what would be the static pressure reading at the faucet?

A

A. 50 psi
B. 59 psi
C. 41 psi
D. 21 psi

22
Q

How would you find the pressure loss when 8 GPM travels through 3/4” class 200 PVC pipe? And what two pieces of information MUST you know in order to get your answer?

A

____. The size of the pipe and the flow of the water.

23
Q

T/F: 1/2” PVC pipe is used to increase the pressure to the last head in a zone.

A

False.

24
Q

In what two ways can pressure be created?

A
  1. Gravity- using the weight of water to create pressure (water tower).
  2. Mechanical Pressure (pump).
25
Q

What does PSI mean?

A

Pounds of pressure exerted per square inch.

26
Q

To express pressure you can use feet of head. Feet of head is the measurement of a column of water. A column of water 1’ high is equal to 1 foot of head, while a 5’ column of water is equal to a pressure of 5 feet of head. If you weighed a column of water, which consisted of 12 cubic inches, how many pounds would the weight at the bottom be equal to?

A

0.433 A column of water 1’ high will exert an equal pressure of .433 psi over the whole base.

27
Q

0.433 is an important number, why?

A

.433 tells us for every 1’ of elevation change, our pressure will change by .433 psi.

28
Q

How do you determine the psi of a column of water?

A

You multiply the height by 0.433. To convert feet of head to psi, multiply the feet of head by .433.

29
Q

15ft/hd = ____psi

A

15 ft/hd x .433 = 6.5 psi

30
Q

To convert PSi into feet of head, all you would have to do is perform the opposite math operation. Divide the psi by .433.

A

1 psi = ___ ft/hd

1 psi / .433 = 2.31 ft/hd

31
Q

water in motion is _____

A

dynamic

32
Q

water at rest is ______

A

static

33
Q

What criteria pertains to the Pressure Vacuum Breaker? (PVB)

A
  1. It protects against back siphonage only.
  2. It can be under constant pressure (more than 12 hours).
  3. It must be installed at least 12” above the highest downstream outlet.
  4. It is approved for potential health hazard conditions.
  5. Must be tested by a licensed backflow prevention assembly tester upon installation and annually if the health hazard conditions exist.
34
Q

Name the parts of an electric valve

A
  1. Flow control
  2. manual bleed screw
  3. diaphragm
  4. inlet port
  5. valve inlet
  6. solenoid
  7. plunger
  8. outlet port
  9. valve outlet
35
Q

Friction loss charts for PVC are based on 100’ lengths. So what do you do if you only have a 30’ piece of 3/4” class 200 PCV carrying 8 GPM?

A

Think of the given length (30’) as a percentage of the 100’ length the charts are based on. The 30’ length needs to be thought of as 30%. or .30.

36
Q

Piping in all irrigation systems must be installed according to manufacturer’s recommendations for depth coverage of piping. If no manufacturer’s recommendations exist, the minimum standards for depth of pipe coverage are what?

A
  1. the irrigation system must be designed and installed to provide a minimum of six (6) inches of coverage over piping up to the natural grade.
  2. Irrigation system must be designed and installed to provide a minimum of two (2) inches of coverage over piping when encountering obstacles like tree roots or utilities. If rock is encountered, select backfill can be mounded over pipe. Mounding is to be noted on the design, and safety issues resulting from the mounding should be discussed with the system’s owner.
  3. All installation trenches and excavations must be backfilled and compacted to original grade.
37
Q

Precipitation rate is calculated how?

A

Inches per hour. GPM (full circle head) x 96.3 divided by head spacing x row spacing
or
Total GPM x 96.3 divided by total area.

38
Q

What is slope and how is it calculated?

A

A measure of the rate of change of elevation over a prescribed distance. Expressed as a ratio, a grade or as a percent. ratio of 1 foot vertical to 4 feet horizontal is the same grade of .25, which is equal to a percent slope of 25%. Slope = Rise / Run

39
Q

What is the criteria of Reduced pressure Principle Backflow Prevention Assembly (RPBA)?

A
  1. It protects against back-siphonage and back pressure.
  2. It can be under constant pressure.
  3. It must be installed with a minimum clearance of 12” between relief port and the floor or grade
  4. It is approved for potential health hazard conditions.
  5. Approved method of backflow prevention when chemicals are added to the system.
  6. Must be tested by a licensed backflow prevention assembly tester upon installation and annually if health hazard conditions exist.
40
Q

What is the criteria for an Atmospheric Vacuum Breaker (AVB)?

A
  1. It is designed to prevent back siphonage only.
  2. It cannot be under constant pressure (more than 12 hours); therefore, no control valves can be installed downstream an AVB.
  3. it must be installed 6” above the highest downstream piping or outlet.
  4. A separate AVB must be installed on the discharge side of each zone valve, between the valve and all sprinkler heads that the valve controls.
  5. It is approved for potential health hazard conditions.
  6. Must be tested by a licensed backflow prevention assembly tester upon installation and annually if health hazard conditions exist.
41
Q

What is the criteria of a Double Check Valve Backflow Prevention Assembly (DVCA)?

A
  1. It protects against back siphonage and back pressure.
  2. It can be under constant pressure.
  3. If installed below grade, it must fit the following criteria;
    a. adequate space must be left for testing and repair.
    b. when not being tested, test cocks must be plugged with water-tight, non-ferrous threaded plugs.
    c. A Y-type strainer is installed on the inlet side of the double check valve.
  4. It is approved for non-health hazard conditions but NOT APPROVED for health hazard conditions.
  5. Must be tested upon installation by a licensed backflow prevention assembly tester.
42
Q

What is the first of the two formulas used to find precipitation rate of your system?

A

Precipitation rate (in/hr)= GPH (one emitter) x 231 divided by Emitter interval x row spacing

43
Q

Give the precipitation rate for a system with 1 GPH emitters on 24” intervals. Each row is 24” apart.

A

PR (in/hr) = 1x231 / 24 x 24 = 231/576 =

.40 in/hr

44
Q

What is the second formula used to find precipitation rate of your system?

A

PR (in/hr) = GPH (one emitter) x 1.6 / wetted area in square feet for 1 emitter

45
Q

What would the application rate for a system with 1 GPH emitters on 24” intervals? each row is 24” apart.

A

PR (in/hr) = 1 x 1.6 / 2 x 2 = 1.6/4 = .4 in/hr

Irrigation Tech Practice Exam (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions