Backflow Prevention Test Your
Knowledge Exam Study Guide
2026/2027 Accurate Questions
with Correct Detailed Solutions ||
100% Guaranteed Pass Newest
Version
Description: This exam covers the principles, regulations, and practical applications of
backflow prevention in plumbing and water supply systems. It tests knowledge on cross-
connections, backflow causes, prevention devices, and testing procedures.
Key Words: Backflow, Cross-Connection, Backsiphonage, Backpressure, RPZ, DCVA,
PVB, AVB, Air Gap, Containment, Isolation, Test Cock, Differential Pressure, Potable
Water, Contamination, Pollution, Hazard, ASSE, USC, Plumbing Code.
1. What is the primary definition of backflow?
A. The normal flow of water from the main to a fixture
B. The reverse flow of water, liquids, or gases into the potable water system ✅
C. The draining of a water heater
D. The process of water filtration
2. What is a cross-connection?
A. A connection between two pipes of the same size
B. Any actual or potential connection between a potable water system and any source of
,contamination ✅
C. A method of joining copper pipes
D. A type of water meter
3. Which of the following is a cause of backflow?
A. Backpressure
B. Backsiphonage
C. Both A and B ✅
D. Thermal expansion
4. What is backsiphonage?
A. Backflow caused by a pressure increase in the potable water system
B. Backflow caused by a negative or reduced pressure in the potable water system ✅
C. A type of pump
D. A method of water treatment
5. What is backpressure?
A. Backflow caused by pressure in a non-potable system exceeding the pressure in the
potable system ✅
B. Backflow caused by a vacuum
C. A type of valve
D. A water hammer effect
6. Which of the following is a typical cause of backsiphonage?
A. A water main break ✅
B. A boiler operating at high pressure
C. A pump in a non-potable system
D. A thermal expansion tank
7. What is the primary purpose of a backflow prevention assembly?
A. To increase water pressure
B. To prevent the reverse flow of contaminants into the potable water supply ✅
,C. To filter water
D. To measure water usage
8. Which of the following is a type of backflow prevention assembly?
A. Reduced Pressure Zone (RPZ) valve ✅
B. Gate valve
C. Check valve
D. Ball valve
9. What does an RPZ valve consist of?
A. Two independently acting check valves and a differential pressure relief valve ✅
B. One check valve and one gate valve
C. A single check valve
D. A pressure gauge only
10. What is a Double Check Valve Assembly (DCVA) primarily used for?
A. High hazard applications
B. Low hazard applications ✅
C. Fire sprinkler systems only
D. Irrigation systems only
11. Which backflow preventer provides the highest level of protection?
A. Air gap ✅
B. DCVA
C. PVB
D. AVB
12. What is an atmospheric vacuum breaker (AVB) designed for?
A. High pressure systems
B. Low hazard, non-continuous pressure applications ✅
C. Continuous pressure applications
D. Submerged applications
, 13. What is a pressure vacuum breaker (PVB) designed for?
A. Low hazard, continuous pressure applications ✅
B. High hazard applications
C. Submerged applications
D. Backpressure applications
14. Which backflow preventer is not allowed to be under continuous pressure for
more than 12 hours?
A. RPZ
B. DCVA
C. AVB ✅
D. PVB
15. What is the minimum air gap required for a backflow prevention air gap?
A. One inch
B. Two times the diameter of the pipe or a minimum of one inch, whichever is greater ✅
C. Half the diameter of the pipe
D. One foot
16. Which of the following is a test for an RPZ valve?
A. Checking the air inlet
B. Testing the differential pressure relief valve opening point ✅
C. Testing the water meter
D. Checking the pipe diameter
17. What does the first check valve in an RPZ do?
A. Maintains a pressure differential between the first and second check valves ✅
B. Relieves pressure
C. Measures flow
D. Shuts off water completely
18. What is the purpose of the relief valve in an RPZ?
A. To discharge water if the differential pressure drops below a certain point ✅
Knowledge Exam Study Guide
2026/2027 Accurate Questions
with Correct Detailed Solutions ||
100% Guaranteed Pass Newest
Version
Description: This exam covers the principles, regulations, and practical applications of
backflow prevention in plumbing and water supply systems. It tests knowledge on cross-
connections, backflow causes, prevention devices, and testing procedures.
Key Words: Backflow, Cross-Connection, Backsiphonage, Backpressure, RPZ, DCVA,
PVB, AVB, Air Gap, Containment, Isolation, Test Cock, Differential Pressure, Potable
Water, Contamination, Pollution, Hazard, ASSE, USC, Plumbing Code.
1. What is the primary definition of backflow?
A. The normal flow of water from the main to a fixture
B. The reverse flow of water, liquids, or gases into the potable water system ✅
C. The draining of a water heater
D. The process of water filtration
2. What is a cross-connection?
A. A connection between two pipes of the same size
B. Any actual or potential connection between a potable water system and any source of
,contamination ✅
C. A method of joining copper pipes
D. A type of water meter
3. Which of the following is a cause of backflow?
A. Backpressure
B. Backsiphonage
C. Both A and B ✅
D. Thermal expansion
4. What is backsiphonage?
A. Backflow caused by a pressure increase in the potable water system
B. Backflow caused by a negative or reduced pressure in the potable water system ✅
C. A type of pump
D. A method of water treatment
5. What is backpressure?
A. Backflow caused by pressure in a non-potable system exceeding the pressure in the
potable system ✅
B. Backflow caused by a vacuum
C. A type of valve
D. A water hammer effect
6. Which of the following is a typical cause of backsiphonage?
A. A water main break ✅
B. A boiler operating at high pressure
C. A pump in a non-potable system
D. A thermal expansion tank
7. What is the primary purpose of a backflow prevention assembly?
A. To increase water pressure
B. To prevent the reverse flow of contaminants into the potable water supply ✅
,C. To filter water
D. To measure water usage
8. Which of the following is a type of backflow prevention assembly?
A. Reduced Pressure Zone (RPZ) valve ✅
B. Gate valve
C. Check valve
D. Ball valve
9. What does an RPZ valve consist of?
A. Two independently acting check valves and a differential pressure relief valve ✅
B. One check valve and one gate valve
C. A single check valve
D. A pressure gauge only
10. What is a Double Check Valve Assembly (DCVA) primarily used for?
A. High hazard applications
B. Low hazard applications ✅
C. Fire sprinkler systems only
D. Irrigation systems only
11. Which backflow preventer provides the highest level of protection?
A. Air gap ✅
B. DCVA
C. PVB
D. AVB
12. What is an atmospheric vacuum breaker (AVB) designed for?
A. High pressure systems
B. Low hazard, non-continuous pressure applications ✅
C. Continuous pressure applications
D. Submerged applications
, 13. What is a pressure vacuum breaker (PVB) designed for?
A. Low hazard, continuous pressure applications ✅
B. High hazard applications
C. Submerged applications
D. Backpressure applications
14. Which backflow preventer is not allowed to be under continuous pressure for
more than 12 hours?
A. RPZ
B. DCVA
C. AVB ✅
D. PVB
15. What is the minimum air gap required for a backflow prevention air gap?
A. One inch
B. Two times the diameter of the pipe or a minimum of one inch, whichever is greater ✅
C. Half the diameter of the pipe
D. One foot
16. Which of the following is a test for an RPZ valve?
A. Checking the air inlet
B. Testing the differential pressure relief valve opening point ✅
C. Testing the water meter
D. Checking the pipe diameter
17. What does the first check valve in an RPZ do?
A. Maintains a pressure differential between the first and second check valves ✅
B. Relieves pressure
C. Measures flow
D. Shuts off water completely
18. What is the purpose of the relief valve in an RPZ?
A. To discharge water if the differential pressure drops below a certain point ✅
