Backflow Prevention Assembly Tester
Certification Exam (ASSE 5110) Practice
Test Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. The primary purpose of backflow prevention is to:
A. Increase system water pressure
B. Reduce water consumption
C. Maintain water velocity
D. Protect the potable water supply
Rationale: Protecting drinking water from contamination due to
backflow is the core purpose of backflow prevention.
2. A cross-connection is best defined as:
A. A leak in a water main
B. A chemical mixing with water
, C. Any actual or potential connection between potable and non-
potable water
D. A pressure loss in a system
Rationale: A cross-connection creates the potential for contaminants
to enter potable water.
3. Backpressure occurs when:
A. The supply pressure increases
B. The downstream pressure becomes greater than the supply
pressure
C. A vacuum is created in the supply line
D. A check valve fails
Rationale: Backpressure is when downstream pressure exceeds
supply pressure, forcing flow backward.
4. Backsiphonage is caused by:
A. Pumps shutting off
B. Check valves closing
C. Negative pressure in the supply line
D. System expansion
Rationale: A vacuum or reduced pressure can siphon contaminants
back into potable water.
5. The most serious type of hazard requiring the highest level of
protection is:
A. Pollutant hazard
, B. Contaminant hazard
C. Fire suppression hazard
D. Leakage hazard
Rationale: Contaminants present health hazards and require the
strongest protection.
6. A Reduced Pressure Principle Assembly (RP) is required when:
A. Only low hazards are present
B. High hazards are present
C. There is no backpressure risk
D. The system is not pressurized
Rationale: RPs provide maximum protection against backpressure
and backsiphonage for high hazards.
7. The two shutoff valves on a testable assembly are:
A. Relief and air inlet valves
B. Isolation valves
C. Drain valves
D. Meter valves
Rationale: Shutoff or isolation valves allow the assembly to be
isolated for testing.
8. A check valve in a backflow preventer must:
A. Always remain open
B. Be sized larger than the pipe
C. Close tightly to prevent reverse flow
Certification Exam (ASSE 5110) Practice
Test Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. The primary purpose of backflow prevention is to:
A. Increase system water pressure
B. Reduce water consumption
C. Maintain water velocity
D. Protect the potable water supply
Rationale: Protecting drinking water from contamination due to
backflow is the core purpose of backflow prevention.
2. A cross-connection is best defined as:
A. A leak in a water main
B. A chemical mixing with water
, C. Any actual or potential connection between potable and non-
potable water
D. A pressure loss in a system
Rationale: A cross-connection creates the potential for contaminants
to enter potable water.
3. Backpressure occurs when:
A. The supply pressure increases
B. The downstream pressure becomes greater than the supply
pressure
C. A vacuum is created in the supply line
D. A check valve fails
Rationale: Backpressure is when downstream pressure exceeds
supply pressure, forcing flow backward.
4. Backsiphonage is caused by:
A. Pumps shutting off
B. Check valves closing
C. Negative pressure in the supply line
D. System expansion
Rationale: A vacuum or reduced pressure can siphon contaminants
back into potable water.
5. The most serious type of hazard requiring the highest level of
protection is:
A. Pollutant hazard
, B. Contaminant hazard
C. Fire suppression hazard
D. Leakage hazard
Rationale: Contaminants present health hazards and require the
strongest protection.
6. A Reduced Pressure Principle Assembly (RP) is required when:
A. Only low hazards are present
B. High hazards are present
C. There is no backpressure risk
D. The system is not pressurized
Rationale: RPs provide maximum protection against backpressure
and backsiphonage for high hazards.
7. The two shutoff valves on a testable assembly are:
A. Relief and air inlet valves
B. Isolation valves
C. Drain valves
D. Meter valves
Rationale: Shutoff or isolation valves allow the assembly to be
isolated for testing.
8. A check valve in a backflow preventer must:
A. Always remain open
B. Be sized larger than the pipe
C. Close tightly to prevent reverse flow
