ASSE 5130 Backflow Prevention
Assembly Repairer Practice Exam 100
Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A Instant Download Pdf
1. What is the primary purpose of a backflow prevention assembly?
A. To increase water pressure
B. To prevent reverse flow of water into the potable supply
C. To filter out impurities
D. To regulate temperature
Rationale: Backflow prevention assemblies are designed to stop
contaminated or non-potable water from reversing into the clean water
system.
2. Which condition causes backpressure backflow?
A. Negative pressure in the supply
B. A decrease in downstream pressure
C. Pressure downstream exceeds supply pressure
D. A vented condition in the supply line
Rationale: When downstream pressure becomes higher than supply pressure,
water can flow backward, causing backpressure backflow.
3. The check valves in a Reduced Pressure Principle Assembly must close tight
when tested at:
A. 0.5 psi
B. Differential pressure greater than 1.0 psi
C. 1.0 psi
D. No differential pressure
,Rationale: The check valves must maintain a differential pressure greater
than 1.0 psi to ensure proper sealing.
4. Which component of a Double Check Valve Assembly (DCVA) prevents
backflow?
A. Two independently acting check valves
B. Air inlet valve
C. Relief valve
D. Shutoff valves only
Rationale: The two check valves act independently to prevent reverse flow,
ensuring redundancy.
5. The relief valve in an RP assembly opens when:
A. There is a pressure drop across the first check
B. The first check leaks and the pressure between checks exceeds supply
C. The supply pressure increases suddenly
D. Downstream pressure is higher than supply
Rationale: The relief valve opens when the pressure in the zone exceeds the
supply pressure due to leakage past the first check.
6. What is the minimum differential pressure required across each check
valve in a DCVA during testing?
A. 0.5 psi
B. 1.0 psi
C. 2.0 psi
D. 3.0 psi
Rationale: Each check must close tight with a minimum of 1.0 psi differential
pressure to pass.
7. A repairer finds debris under the check valve disc. What is the most
appropriate repair step?
A. Replace the entire assembly
B. Clean the check seat and disc
C. Replace the disc with an oversized one
D. Install a new test cock
, Rationale: Debris on the seat prevents sealing; cleaning the seat and disc
usually resolves the issue.
8. What type of backflow results when the supply pressure drops below
atmospheric pressure?
A. Backpressure
B. Backsiphonage
C. Cross-connection
D. Pressure surge
Rationale: Backsiphonage occurs when negative pressure draws water
backward into the potable system.
9. Which test instrument is used by backflow assembly testers and repairers?
A. Manometer
B. Differential pressure gauge
C. Flow meter
D. Vacuum gauge
Rationale: The differential pressure gauge measures pressure differences
across check valves and relief valves.
10. Before disassembling an RP assembly for repair, what should be done
first?
A. Close downstream shutoff valve only
B. Close both shutoff valves and relieve pressure
C. Open the relief valve
D. Drain the upstream piping
Rationale: Always isolate the assembly and relieve internal pressure before
repair for safety.
11. A leaking #1 check in an RP assembly may cause what symptom during
testing?
A. Relief valve discharge
B. No flow through test cock #2
C. Pressure buildup downstream
D. Relief valve stays closed
Assembly Repairer Practice Exam 100
Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A Instant Download Pdf
1. What is the primary purpose of a backflow prevention assembly?
A. To increase water pressure
B. To prevent reverse flow of water into the potable supply
C. To filter out impurities
D. To regulate temperature
Rationale: Backflow prevention assemblies are designed to stop
contaminated or non-potable water from reversing into the clean water
system.
2. Which condition causes backpressure backflow?
A. Negative pressure in the supply
B. A decrease in downstream pressure
C. Pressure downstream exceeds supply pressure
D. A vented condition in the supply line
Rationale: When downstream pressure becomes higher than supply pressure,
water can flow backward, causing backpressure backflow.
3. The check valves in a Reduced Pressure Principle Assembly must close tight
when tested at:
A. 0.5 psi
B. Differential pressure greater than 1.0 psi
C. 1.0 psi
D. No differential pressure
,Rationale: The check valves must maintain a differential pressure greater
than 1.0 psi to ensure proper sealing.
4. Which component of a Double Check Valve Assembly (DCVA) prevents
backflow?
A. Two independently acting check valves
B. Air inlet valve
C. Relief valve
D. Shutoff valves only
Rationale: The two check valves act independently to prevent reverse flow,
ensuring redundancy.
5. The relief valve in an RP assembly opens when:
A. There is a pressure drop across the first check
B. The first check leaks and the pressure between checks exceeds supply
C. The supply pressure increases suddenly
D. Downstream pressure is higher than supply
Rationale: The relief valve opens when the pressure in the zone exceeds the
supply pressure due to leakage past the first check.
6. What is the minimum differential pressure required across each check
valve in a DCVA during testing?
A. 0.5 psi
B. 1.0 psi
C. 2.0 psi
D. 3.0 psi
Rationale: Each check must close tight with a minimum of 1.0 psi differential
pressure to pass.
7. A repairer finds debris under the check valve disc. What is the most
appropriate repair step?
A. Replace the entire assembly
B. Clean the check seat and disc
C. Replace the disc with an oversized one
D. Install a new test cock
, Rationale: Debris on the seat prevents sealing; cleaning the seat and disc
usually resolves the issue.
8. What type of backflow results when the supply pressure drops below
atmospheric pressure?
A. Backpressure
B. Backsiphonage
C. Cross-connection
D. Pressure surge
Rationale: Backsiphonage occurs when negative pressure draws water
backward into the potable system.
9. Which test instrument is used by backflow assembly testers and repairers?
A. Manometer
B. Differential pressure gauge
C. Flow meter
D. Vacuum gauge
Rationale: The differential pressure gauge measures pressure differences
across check valves and relief valves.
10. Before disassembling an RP assembly for repair, what should be done
first?
A. Close downstream shutoff valve only
B. Close both shutoff valves and relieve pressure
C. Open the relief valve
D. Drain the upstream piping
Rationale: Always isolate the assembly and relieve internal pressure before
repair for safety.
11. A leaking #1 check in an RP assembly may cause what symptom during
testing?
A. Relief valve discharge
B. No flow through test cock #2
C. Pressure buildup downstream
D. Relief valve stays closed
