Virginia Backflow Prevention Device
Worker Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
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1. In potable water distribution systems, the primary purpose of a
backflow prevention device is to prevent which condition from
contaminating the public water supply?
A. Excessive water pressure in municipal mains
B. Reverse flow of contaminated water into the potable supply
C. Increased water velocity in branch piping
D. Sediment accumulation in storage tanks
The correct answer is B because backflow prevention devices are
specifically designed to stop reverse flow, which can occur through
backpressure or backsiphonage and allow contaminants to enter potable
water systems.
2. Which condition most commonly causes backsiphonage in a plumbing
system?
A. High pressure within the supply line
B. Negative pressure in the supply piping
C. Excessive temperature within the piping
D. Mechanical failure of water meters
,The correct answer is B because backsiphonage occurs when the pressure
in the supply line drops below atmospheric pressure, creating a vacuum
that can draw contaminated water back into the potable supply.
3. Which type of backflow condition occurs when downstream pressure
exceeds the supply pressure?
A. Backsiphonage
B. Static pressure loss
C. Backpressure
D. Cross-connection vacuum
The correct answer is C because backpressure occurs when downstream
pressure becomes greater than upstream supply pressure, forcing water to
flow backward into the potable system.
4. A cross-connection is best defined as which of the following?
A. A pipe connection between two water meters
B. A connection between hot and cold water lines
C. A link between potable water and a potential contaminant source
D. A connection between two municipal water systems
The correct answer is C because a cross-connection is any physical
connection between potable water and a non-potable source that could
allow contamination through backflow.
5. Which device protects against backsiphonage but not backpressure?
A. Reduced pressure principle assembly
B. Double check valve assembly
C. Atmospheric vacuum breaker
D. Pressure vacuum breaker
The correct answer is C because atmospheric vacuum breakers only protect
against backsiphonage and cannot be used where backpressure conditions
exist.
6. An atmospheric vacuum breaker must be installed at least how far
above the highest downstream outlet it serves?
, A. 1 inch
B. 3 inches
C. 6 inches
D. 18 inches
The correct answer is C because atmospheric vacuum breakers require
installation at least 6 inches above the highest outlet to ensure proper
operation during siphon conditions.
7. Which backflow prevention assembly is designed to protect against
both backsiphonage and backpressure hazards and includes a relief
valve?
A. Atmospheric vacuum breaker
B. Hose bib vacuum breaker
C. Double check valve assembly
D. Reduced pressure principle assembly
The correct answer is D because a reduced pressure principle assembly
contains two check valves and a pressure-monitored relief valve, providing
protection from both backpressure and backsiphonage.
8. A double check valve assembly primarily protects against which type
of hazard?
A. High health hazard contamination
B. Low to moderate hazard backflow conditions
C. Industrial chemical contamination
D. Toxic waste backflow
The correct answer is B because double check valve assemblies are
typically used where contaminants pose a non-health hazard risk to the
potable water supply.
9. What is the primary function of check valves within a double check
valve assembly?
A. To increase water pressure
B. To filter contaminants
Worker Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. In potable water distribution systems, the primary purpose of a
backflow prevention device is to prevent which condition from
contaminating the public water supply?
A. Excessive water pressure in municipal mains
B. Reverse flow of contaminated water into the potable supply
C. Increased water velocity in branch piping
D. Sediment accumulation in storage tanks
The correct answer is B because backflow prevention devices are
specifically designed to stop reverse flow, which can occur through
backpressure or backsiphonage and allow contaminants to enter potable
water systems.
2. Which condition most commonly causes backsiphonage in a plumbing
system?
A. High pressure within the supply line
B. Negative pressure in the supply piping
C. Excessive temperature within the piping
D. Mechanical failure of water meters
,The correct answer is B because backsiphonage occurs when the pressure
in the supply line drops below atmospheric pressure, creating a vacuum
that can draw contaminated water back into the potable supply.
3. Which type of backflow condition occurs when downstream pressure
exceeds the supply pressure?
A. Backsiphonage
B. Static pressure loss
C. Backpressure
D. Cross-connection vacuum
The correct answer is C because backpressure occurs when downstream
pressure becomes greater than upstream supply pressure, forcing water to
flow backward into the potable system.
4. A cross-connection is best defined as which of the following?
A. A pipe connection between two water meters
B. A connection between hot and cold water lines
C. A link between potable water and a potential contaminant source
D. A connection between two municipal water systems
The correct answer is C because a cross-connection is any physical
connection between potable water and a non-potable source that could
allow contamination through backflow.
5. Which device protects against backsiphonage but not backpressure?
A. Reduced pressure principle assembly
B. Double check valve assembly
C. Atmospheric vacuum breaker
D. Pressure vacuum breaker
The correct answer is C because atmospheric vacuum breakers only protect
against backsiphonage and cannot be used where backpressure conditions
exist.
6. An atmospheric vacuum breaker must be installed at least how far
above the highest downstream outlet it serves?
, A. 1 inch
B. 3 inches
C. 6 inches
D. 18 inches
The correct answer is C because atmospheric vacuum breakers require
installation at least 6 inches above the highest outlet to ensure proper
operation during siphon conditions.
7. Which backflow prevention assembly is designed to protect against
both backsiphonage and backpressure hazards and includes a relief
valve?
A. Atmospheric vacuum breaker
B. Hose bib vacuum breaker
C. Double check valve assembly
D. Reduced pressure principle assembly
The correct answer is D because a reduced pressure principle assembly
contains two check valves and a pressure-monitored relief valve, providing
protection from both backpressure and backsiphonage.
8. A double check valve assembly primarily protects against which type
of hazard?
A. High health hazard contamination
B. Low to moderate hazard backflow conditions
C. Industrial chemical contamination
D. Toxic waste backflow
The correct answer is B because double check valve assemblies are
typically used where contaminants pose a non-health hazard risk to the
potable water supply.
9. What is the primary function of check valves within a double check
valve assembly?
A. To increase water pressure
B. To filter contaminants
