BACKFLOW DEFINITIONS CHAPTER 1
EXAM QUESTIONS AND ANSWERS
Absolute Pressure - Correct Answers -Pressure measured on a scale where a perfect
vacuum is zero.
Absolute Pressure 2 - Correct Answers -The sum of gauge pressure and atmospheric
pressure
Accessible - Correct Answers -Capable of being reached for testing and maintenance,
when referring to a backflow assembly. May also require the removal of an access
panel.
Atmospheric Pressure - Correct Answers -Th prssure (or weight per unit area) exerted
by the atmosphere on a surface. At sea level the atmospheric pressure is 14.7 psia
(pounds per square inch absolute)
Atmospheric Vacuum Breaker Backsiphonage Prevention Assembly (AVB) - Correct
Answers -An assembly containing an air inlet valve, a check seat and an air inlet port(s).
(Also known as the non pressure type vacuum breaker).
How does the AVB work? - Correct Answers -The flow of water into the body causes the
air inlet valve to close the air inlet port(s). When the flow of water stops, the air inlet
valve falls and forms a check valve against backsiphonage. At the same time it opens
the air inlet port(s), allowing air to enter and satisfy the vacuum.
Administrative Authority - Correct Answers -The individual offical, board, department, or
agency established and authorized by a state, country, city or other political entity
created by law to administer and enforce the provisions of the cross connection control
program
Air Gap - Correct Answers -A physical separation between the free flowing discharge
end of a potable water supply pipeline and and open or non-presssure receiving vessel.
Air Gap Specs - Correct Answers -An approved air gap shall be at least twice the
diameter of the supply pipe measured vertically above the overflow rim of the receiving
vessel (in no case less than 1 inch)
Approved Backflow Prvention Assembly - Correct Answers -An assembly that has been
investigated and approved by the administrative authority having jurisdiction. The
approval of backflow prevention assemblies by the administrative authority shall be on
EXAM QUESTIONS AND ANSWERS
Absolute Pressure - Correct Answers -Pressure measured on a scale where a perfect
vacuum is zero.
Absolute Pressure 2 - Correct Answers -The sum of gauge pressure and atmospheric
pressure
Accessible - Correct Answers -Capable of being reached for testing and maintenance,
when referring to a backflow assembly. May also require the removal of an access
panel.
Atmospheric Pressure - Correct Answers -Th prssure (or weight per unit area) exerted
by the atmosphere on a surface. At sea level the atmospheric pressure is 14.7 psia
(pounds per square inch absolute)
Atmospheric Vacuum Breaker Backsiphonage Prevention Assembly (AVB) - Correct
Answers -An assembly containing an air inlet valve, a check seat and an air inlet port(s).
(Also known as the non pressure type vacuum breaker).
How does the AVB work? - Correct Answers -The flow of water into the body causes the
air inlet valve to close the air inlet port(s). When the flow of water stops, the air inlet
valve falls and forms a check valve against backsiphonage. At the same time it opens
the air inlet port(s), allowing air to enter and satisfy the vacuum.
Administrative Authority - Correct Answers -The individual offical, board, department, or
agency established and authorized by a state, country, city or other political entity
created by law to administer and enforce the provisions of the cross connection control
program
Air Gap - Correct Answers -A physical separation between the free flowing discharge
end of a potable water supply pipeline and and open or non-presssure receiving vessel.
Air Gap Specs - Correct Answers -An approved air gap shall be at least twice the
diameter of the supply pipe measured vertically above the overflow rim of the receiving
vessel (in no case less than 1 inch)
Approved Backflow Prvention Assembly - Correct Answers -An assembly that has been
investigated and approved by the administrative authority having jurisdiction. The
approval of backflow prevention assemblies by the administrative authority shall be on
