ASSE 5110 Backflow Prevention
Assembly Tester 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 filter particulate matter from water
C. To prevent contamination of the potable water supply
D. To regulate water temperature
C. To prevent contamination of the potable water supply
Backflow prevention assemblies protect drinking water from contamination
or pollution caused by the reverse flow of non-potable substances into the
potable system.
2. Backflow is defined as:
A. Flow in the normal intended direction
B. Flow of water or other substances in the opposite direction from its
intended path
C. A reduction in downstream pressure
D. The forward flow through a valve
B. Flow of water or other substances in the opposite direction from its
intended path
Backflow occurs when the direction of flow reverses, potentially introducing
contaminants into potable water systems.
,3. Backpressure backflow occurs when:
A. Supply pressure increases significantly
B. Supply pressure decreases below atmospheric
C. Downstream pressure exceeds supply pressure
D. There is no pressure differential in the system
C. Downstream pressure exceeds supply pressure
When downstream pressure becomes greater than the supply pressure, fluids
can be forced backward into the potable system. This can result from pumps,
elevated tanks, or thermal expansion.
4. Back-siphonage backflow is caused by:
A. Increased downstream pressure from a booster pump
B. A drop in supply pressure below atmospheric pressure
C. Pump failure in a closed system
D. Air entrapment in the piping
B. A drop in supply pressure below atmospheric pressure
Back-siphonage happens when supply pressure drops, creating a vacuum or
negative pressure that draws contaminants backward into the potable
system. Examples include water main breaks and firefighting demand.
5. Which backflow prevention assembly provides the highest level of
protection?
A. Double check valve assembly (DCVA)
B. Pressure vacuum breaker (PVB)
C. Spill-resistant vacuum breaker (SVB)
D. Reduced pressure principle assembly (RP)
D. Reduced pressure principle assembly (RP)
,RP assemblies provide the highest protection level because they have a relief
valve that discharges contaminants and protects against both backpressure
and backsiphonage.
6. The test cocks on a double check valve assembly are used to:
A. Connect test equipment and measure differential pressure
B. Drain water from the assembly during maintenance
C. Control the direction of flow through the assembly
D. Relieve excess pressure from the system
A. Connect test equipment and measure differential pressure
Test cocks allow testers to attach gauges and measure pressure differences
across check valves during field testing.
7. The minimum pressure differential required for a check valve in a DCVA to
be considered functional is:
A. 1.0 psi
B. 2.0 psi
C. 3.0 psi
D. 0.5 psi
A. 1.0 psi
Each check valve in a DCVA must maintain at least 1.0 psi to be acceptable
under ASSE 5110 standards.
8. The relief valve in an RP assembly must open before:
A. The first check valve closes completely
B. The differential pressure across the first check drops below 2.0 psi
C. The second check valve opens
D. Supply pressure increases above normal
B. The differential pressure across the first check drops below 2.0 psi
, This ensures any backpressure or backsiphonage is vented safely, maintaining
system protection. The relief valve opens when the zone pressure becomes
unsafe.
9. Which tool is essential for performing a backflow test?
A. Torque wrench
B. Pressure gauge only
C. Differential pressure gauge
D. Manometer
C. Differential pressure gauge
Differential pressure gauges measure the pressure drop across test points,
which is critical for accurate testing of backflow prevention assemblies.
10. When testing an RP assembly, the relief valve should open when the
pressure differential across check valve #1 drops below:
A. 1.0 psi
B. 2.0 psi
C. 3.0 psi
D. 5.0 psi
B. 2.0 psi
The relief valve opening point is a critical performance requirement. It must
open at or above the minimum of 2.0 psid to protect against contamination.
11. A cross-connection is best defined as:
A. Any leak in a water main distribution system
B. Any actual or potential connection between a potable water system and a
source of contamination
C. A chemical mixing with water in a storage tank
D. A temporary connection between two garden hoses
Assembly Tester 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 filter particulate matter from water
C. To prevent contamination of the potable water supply
D. To regulate water temperature
C. To prevent contamination of the potable water supply
Backflow prevention assemblies protect drinking water from contamination
or pollution caused by the reverse flow of non-potable substances into the
potable system.
2. Backflow is defined as:
A. Flow in the normal intended direction
B. Flow of water or other substances in the opposite direction from its
intended path
C. A reduction in downstream pressure
D. The forward flow through a valve
B. Flow of water or other substances in the opposite direction from its
intended path
Backflow occurs when the direction of flow reverses, potentially introducing
contaminants into potable water systems.
,3. Backpressure backflow occurs when:
A. Supply pressure increases significantly
B. Supply pressure decreases below atmospheric
C. Downstream pressure exceeds supply pressure
D. There is no pressure differential in the system
C. Downstream pressure exceeds supply pressure
When downstream pressure becomes greater than the supply pressure, fluids
can be forced backward into the potable system. This can result from pumps,
elevated tanks, or thermal expansion.
4. Back-siphonage backflow is caused by:
A. Increased downstream pressure from a booster pump
B. A drop in supply pressure below atmospheric pressure
C. Pump failure in a closed system
D. Air entrapment in the piping
B. A drop in supply pressure below atmospheric pressure
Back-siphonage happens when supply pressure drops, creating a vacuum or
negative pressure that draws contaminants backward into the potable
system. Examples include water main breaks and firefighting demand.
5. Which backflow prevention assembly provides the highest level of
protection?
A. Double check valve assembly (DCVA)
B. Pressure vacuum breaker (PVB)
C. Spill-resistant vacuum breaker (SVB)
D. Reduced pressure principle assembly (RP)
D. Reduced pressure principle assembly (RP)
,RP assemblies provide the highest protection level because they have a relief
valve that discharges contaminants and protects against both backpressure
and backsiphonage.
6. The test cocks on a double check valve assembly are used to:
A. Connect test equipment and measure differential pressure
B. Drain water from the assembly during maintenance
C. Control the direction of flow through the assembly
D. Relieve excess pressure from the system
A. Connect test equipment and measure differential pressure
Test cocks allow testers to attach gauges and measure pressure differences
across check valves during field testing.
7. The minimum pressure differential required for a check valve in a DCVA to
be considered functional is:
A. 1.0 psi
B. 2.0 psi
C. 3.0 psi
D. 0.5 psi
A. 1.0 psi
Each check valve in a DCVA must maintain at least 1.0 psi to be acceptable
under ASSE 5110 standards.
8. The relief valve in an RP assembly must open before:
A. The first check valve closes completely
B. The differential pressure across the first check drops below 2.0 psi
C. The second check valve opens
D. Supply pressure increases above normal
B. The differential pressure across the first check drops below 2.0 psi
, This ensures any backpressure or backsiphonage is vented safely, maintaining
system protection. The relief valve opens when the zone pressure becomes
unsafe.
9. Which tool is essential for performing a backflow test?
A. Torque wrench
B. Pressure gauge only
C. Differential pressure gauge
D. Manometer
C. Differential pressure gauge
Differential pressure gauges measure the pressure drop across test points,
which is critical for accurate testing of backflow prevention assemblies.
10. When testing an RP assembly, the relief valve should open when the
pressure differential across check valve #1 drops below:
A. 1.0 psi
B. 2.0 psi
C. 3.0 psi
D. 5.0 psi
B. 2.0 psi
The relief valve opening point is a critical performance requirement. It must
open at or above the minimum of 2.0 psid to protect against contamination.
11. A cross-connection is best defined as:
A. Any leak in a water main distribution system
B. Any actual or potential connection between a potable water system and a
source of contamination
C. A chemical mixing with water in a storage tank
D. A temporary connection between two garden hoses
