BACKFLOW PREVENTION UPDATED
COMPLETE QUESTIONS AND CORRECT
ANSWERS BUNDLED RESOURCE
●● Which of the following devices is not testable in line?
Answer: Dual check valve
●● What type of hazard does a double check backflow prevention
assembly protect against?
Answer: Low hazard backpressure or backsiphonage
●● What could cause the air inlet valve of a pressure vacuum breaker
assembly to fail to open at 1 psi minimum?
Answer: Weak spring load, air inlet valve seal adhering to bonnet, or
debris restricting free operation
●● What is a critical component subject to failure in an atmospheric type
vacuum breaker?
Answer: Air inlet valve
●● Which conditions can cause backsiphonage?
Answer: Undersized lines, line breaks, or flushing lines through hydrants
,●● What is considered a backflow prevention device?
Answer: Atmospheric type vacuum breaker, pressure vacuum breaker, or
reduced pressure principle
●● What is the pressure drop requirement across the first check of a
reduced pressure principle backflow preventer?
Answer: Must be 1 psi differential
●● One atmosphere is equivalent to what height of water column at sea
level?
Answer: 33.9 foot column of water
●● What is the minimum installation height for a double check backflow
prevention assembly?
Answer: Twelve inches above the highest point of use
●● What absolute pressure could cause backsiphonage in a hydraulic
system at sea level?
Answer: 10.5 psia
●● Why is test cock four opened while flushing the remaining test
***** on a reduced pressure principle backflow preventer?
Answer: To establish a static pressure equilibrium in the assembly
, ●● An air gap separation is measured from the outlet to what point?
Answer: Flood level rim of the receptacle
●● What happens during a static condition if a #2 check valve is fouled?
Answer: Discharge from the relief port
●● What does a reduced pressure principle backflow preventer's relief
valve operate from?
Answer: The inlet water pressure and the water pressure in the
intermediate zone
●● What does equal pressure between a check's inlet and outlet in a
double check backflow prevention assembly suggest?
Answer: The check has failed
●● Which is not a requirement when installing a pressure vacuum
breaker assembly?
Answer: PVB's must be installed at a right angle from the service line
●● What condition would not cause a properly operating pressure
differential relief valve to open?
Answer: A leaking #1 check valve
COMPLETE QUESTIONS AND CORRECT
ANSWERS BUNDLED RESOURCE
●● Which of the following devices is not testable in line?
Answer: Dual check valve
●● What type of hazard does a double check backflow prevention
assembly protect against?
Answer: Low hazard backpressure or backsiphonage
●● What could cause the air inlet valve of a pressure vacuum breaker
assembly to fail to open at 1 psi minimum?
Answer: Weak spring load, air inlet valve seal adhering to bonnet, or
debris restricting free operation
●● What is a critical component subject to failure in an atmospheric type
vacuum breaker?
Answer: Air inlet valve
●● Which conditions can cause backsiphonage?
Answer: Undersized lines, line breaks, or flushing lines through hydrants
,●● What is considered a backflow prevention device?
Answer: Atmospheric type vacuum breaker, pressure vacuum breaker, or
reduced pressure principle
●● What is the pressure drop requirement across the first check of a
reduced pressure principle backflow preventer?
Answer: Must be 1 psi differential
●● One atmosphere is equivalent to what height of water column at sea
level?
Answer: 33.9 foot column of water
●● What is the minimum installation height for a double check backflow
prevention assembly?
Answer: Twelve inches above the highest point of use
●● What absolute pressure could cause backsiphonage in a hydraulic
system at sea level?
Answer: 10.5 psia
●● Why is test cock four opened while flushing the remaining test
***** on a reduced pressure principle backflow preventer?
Answer: To establish a static pressure equilibrium in the assembly
, ●● An air gap separation is measured from the outlet to what point?
Answer: Flood level rim of the receptacle
●● What happens during a static condition if a #2 check valve is fouled?
Answer: Discharge from the relief port
●● What does a reduced pressure principle backflow preventer's relief
valve operate from?
Answer: The inlet water pressure and the water pressure in the
intermediate zone
●● What does equal pressure between a check's inlet and outlet in a
double check backflow prevention assembly suggest?
Answer: The check has failed
●● Which is not a requirement when installing a pressure vacuum
breaker assembly?
Answer: PVB's must be installed at a right angle from the service line
●● What condition would not cause a properly operating pressure
differential relief valve to open?
Answer: A leaking #1 check valve
