BACKFLOW PREVENTION STUDY EXAMS GUIDE
ALL QUESTIONS AND ANSWERS SURE A+
✔✔In what direction is check valve number 1 of a reduced pressure principle assembly
field tested? - ✔✔In the direction of flow.
✔✔What is the purpose of a containment backflow prevention assembly? - ✔✔To
isolate the customer's facility from the public water system.
✔✔What hazard classification is a lawn irrigation system without chemical injection? -
✔✔High hazard.
✔✔What does a post-mix beverage dispenser require to avoid chemical reactions? -
✔✔A backflow preventer.
✔✔How high must a spill-resistant vacuum breaker's critical level be installed above the
highest outlet? - ✔✔At least 12 inches (30 cm).
✔✔What happens if modifications are made to a backflow preventer? - ✔✔It voids its
approval.
, ✔✔What is the maximum plumbing code requirement for water system pressures? -
✔✔80 PSI (555 kPa).
✔✔What is the purpose of two valves in a five-valve test gauge? - ✔✔To purge trap air
from the gauge to the test cock.
✔✔What is the minimum water height required at the check inlet when testing a double
check valve assembly? - ✔✔At least 28 inches (71 cm).
✔✔Why are test ***** flushed before testing a backflow preventer? - ✔✔To clear dirt
and possible corrosion buildup.
✔✔What must be maintained when testing a backflow preventer using a differential
gauge? - ✔✔The gauge and hose connections must be at the same height as the
assembly.
✔✔Why is shut-off valve 2 closed before shut-off valve 1 during backflow preventer
testing? - ✔✔To maintain water pressure for testing.
✔✔What temperature defines hot water according to plumbing codes? - ✔✔Above
120°F (60°C).
✔✔What must a tester obtain before shutting down the water service for testing? -
✔✔Permission.
✔✔What should a tester expect when both shut-off valves are closed on a reduced
pressure principle assembly? - ✔✔Relief valve discharge.
✔✔What is likely the cause of discharge in a reduced pressure principle assembly? -
✔✔A fouled check valve number 1.
✔✔What component forces the relief valve open in a backflow preventer? - ✔✔The
relief valve spring.
✔✔What may cause a pressure vacuum breaker air-inlet not to open during field
testing? - ✔✔A leaking shut-off valve 2 in a parallel installation.
✔✔What is required for a closed plumbing system created by a backflow preventer? -
✔✔The installation of a plumbing system expansion tank.
✔✔What is the differential pressure needed to close a check valve in a dual check? -
✔✔1 PSI (6.9 kPa).
ALL QUESTIONS AND ANSWERS SURE A+
✔✔In what direction is check valve number 1 of a reduced pressure principle assembly
field tested? - ✔✔In the direction of flow.
✔✔What is the purpose of a containment backflow prevention assembly? - ✔✔To
isolate the customer's facility from the public water system.
✔✔What hazard classification is a lawn irrigation system without chemical injection? -
✔✔High hazard.
✔✔What does a post-mix beverage dispenser require to avoid chemical reactions? -
✔✔A backflow preventer.
✔✔How high must a spill-resistant vacuum breaker's critical level be installed above the
highest outlet? - ✔✔At least 12 inches (30 cm).
✔✔What happens if modifications are made to a backflow preventer? - ✔✔It voids its
approval.
, ✔✔What is the maximum plumbing code requirement for water system pressures? -
✔✔80 PSI (555 kPa).
✔✔What is the purpose of two valves in a five-valve test gauge? - ✔✔To purge trap air
from the gauge to the test cock.
✔✔What is the minimum water height required at the check inlet when testing a double
check valve assembly? - ✔✔At least 28 inches (71 cm).
✔✔Why are test ***** flushed before testing a backflow preventer? - ✔✔To clear dirt
and possible corrosion buildup.
✔✔What must be maintained when testing a backflow preventer using a differential
gauge? - ✔✔The gauge and hose connections must be at the same height as the
assembly.
✔✔Why is shut-off valve 2 closed before shut-off valve 1 during backflow preventer
testing? - ✔✔To maintain water pressure for testing.
✔✔What temperature defines hot water according to plumbing codes? - ✔✔Above
120°F (60°C).
✔✔What must a tester obtain before shutting down the water service for testing? -
✔✔Permission.
✔✔What should a tester expect when both shut-off valves are closed on a reduced
pressure principle assembly? - ✔✔Relief valve discharge.
✔✔What is likely the cause of discharge in a reduced pressure principle assembly? -
✔✔A fouled check valve number 1.
✔✔What component forces the relief valve open in a backflow preventer? - ✔✔The
relief valve spring.
✔✔What may cause a pressure vacuum breaker air-inlet not to open during field
testing? - ✔✔A leaking shut-off valve 2 in a parallel installation.
✔✔What is required for a closed plumbing system created by a backflow preventer? -
✔✔The installation of a plumbing system expansion tank.
✔✔What is the differential pressure needed to close a check valve in a dual check? -
✔✔1 PSI (6.9 kPa).
