Ch. 5 - Methods & Mechanism of Preventing Backflow
questions with accurate answers
A assembly is the entire Backflow prevention unit including:
a. Testcocks
b. Shut off valves, test cocks & mechanism.
c. Shut off valves & mechanism. Ans✓✓✓ b. Not only the mechanism
that actually prevents backflow but also the shut off valves of test cocks.
A major disadvantage of an air gap is what:
a. Spilling water
b. Loss of pressure.
c. Not having a shut off valve. Ans✓✓✓ b. Loss of pressure
Air Gap provides the only absolute method for what:
a. High pressure
b. Continuous pressure
c. Preventing backflow Ans✓✓✓ c. Preventing backflow.
Approved assemblies must be shipped from manufacture as:
a. Half a unit.
b. Not assembled.
c. One complete unit. Ans✓✓✓ c. One complete unit
, Atmospheric Vacuum Breaker (AVB) are approved by:
a. A.S.S.E (American Society of Sanitary Engineering)
b. Plumbers.
c. Local government. Ans✓✓✓ a. Are the simplest type of mechanical
backflow preventer that are currently approved by the A.S.S.E (american
society of sanitary engineering).
AVB can be used for protection against:
a. Backsiphnoage only.
b. Backpressure only.
c. Backpressure and Backsiphnoage only. Ans✓✓✓ a. Backsiphonage
but not against backpressure
AVB during Backsiphonage: when the water pressure falls below
atmospheric pressure the disc float on the AVB will do what:
a. Falls and let air enter the top to form an Air Gap.
b. Stay fixed to let water flow through.
c. Falls and let's air into the top to stop backpressure Ans✓✓✓ a. Falls
and let air enter the top to form an Air Gap
AVB must be installed how many inches the highest point in the system.
a. 3 inches.
b. 12 inches
c. 6 inches Ans✓✓✓ c. 6 inches
questions with accurate answers
A assembly is the entire Backflow prevention unit including:
a. Testcocks
b. Shut off valves, test cocks & mechanism.
c. Shut off valves & mechanism. Ans✓✓✓ b. Not only the mechanism
that actually prevents backflow but also the shut off valves of test cocks.
A major disadvantage of an air gap is what:
a. Spilling water
b. Loss of pressure.
c. Not having a shut off valve. Ans✓✓✓ b. Loss of pressure
Air Gap provides the only absolute method for what:
a. High pressure
b. Continuous pressure
c. Preventing backflow Ans✓✓✓ c. Preventing backflow.
Approved assemblies must be shipped from manufacture as:
a. Half a unit.
b. Not assembled.
c. One complete unit. Ans✓✓✓ c. One complete unit
, Atmospheric Vacuum Breaker (AVB) are approved by:
a. A.S.S.E (American Society of Sanitary Engineering)
b. Plumbers.
c. Local government. Ans✓✓✓ a. Are the simplest type of mechanical
backflow preventer that are currently approved by the A.S.S.E (american
society of sanitary engineering).
AVB can be used for protection against:
a. Backsiphnoage only.
b. Backpressure only.
c. Backpressure and Backsiphnoage only. Ans✓✓✓ a. Backsiphonage
but not against backpressure
AVB during Backsiphonage: when the water pressure falls below
atmospheric pressure the disc float on the AVB will do what:
a. Falls and let air enter the top to form an Air Gap.
b. Stay fixed to let water flow through.
c. Falls and let's air into the top to stop backpressure Ans✓✓✓ a. Falls
and let air enter the top to form an Air Gap
AVB must be installed how many inches the highest point in the system.
a. 3 inches.
b. 12 inches
c. 6 inches Ans✓✓✓ c. 6 inches
