BAT Backflow Assembly Tester Prevention Methods 2 — Questions and Answers
Question 1: Which backflow prevention assembly is the ONLY type approved for use on high-hazard connections to the potable water supply?
- Double check valve assembly
- Pressure vacuum breaker
- Reduced pressure principle assembly (Correct answer)
- Atmospheric vacuum breaker
Correct answer: Reduced pressure principle assembly
The reduced pressure principle (RP) assembly is required for high-hazard (toxic/health hazard) connections because it provides the highest level of protection via its relief valve.
Question 2: During a field test of a double check valve assembly, the tester finds that check valve #1 holds at 3.0 psi and check valve #2 holds at 2.5 psi. What is the correct interpretation?
- The assembly passes because both checks hold above 1.0 psi (Correct answer)
- The assembly fails because check #1 must hold at least 5.0 psi
- The assembly fails because check #2 must hold at least 3.0 psi
- The assembly passes only if the static line pressure is above 25 psi
Correct answer: The assembly passes because both checks hold above 1.0 psi
For a DC assembly, both check valves must hold tight at a minimum of 1.0 psi differential; 3.0 and 2.5 psi both exceed this threshold, so the assembly passes.
Question 3: A pressure vacuum breaker (PVB) is installed 6 inches above the highest downstream outlet. Why is this installation non-compliant?
- PVBs must be installed at least 6 inches below the highest outlet
- PVBs must be installed at least 12 inches above the highest downstream outlet (Correct answer)
- PVBs are not approved for use outdoors
- The PVB canister must face horizontally, not vertically
Correct answer: PVBs must be installed at least 12 inches above the highest downstream outlet
ASSE 1020 and most jurisdictional codes require a PVB to be installed a minimum of 12 inches above the highest downstream outlet or point of use.
Question 4: What condition causes the relief valve of an RP assembly to open during normal system operation?
- Supply pressure exceeds 80 psi
- The differential pressure across check #1 falls below 2 psi (Correct answer)
- Downstream demand drops to zero
- The air-inlet valve fails open
Correct answer: The differential pressure across check #1 falls below 2 psi
The RP relief valve is designed to open and discharge to atmosphere when the differential pressure across check valve #1 falls below 2 psi, preventing backpressure or backsiphonage from reaching the supply.
Question 5: An atmospheric vacuum breaker (AVB) is being tested in the field. Which statement about field testing AVBs is correct?
- AVBs must be field tested annually using a differential pressure gauge
- AVBs are not field testable and rely on visual inspection only (Correct answer)
- AVBs are field tested by applying backpressure and reading the gauge
- AVBs are tested by measuring the outlet pressure under flowing conditions
Correct answer: AVBs are not field testable and rely on visual inspection only
Atmospheric vacuum breakers (ASSE 1001) are non-testable assemblies; they are assessed through visual inspection of the air-inlet valve and float mechanism rather than a differential pressure test.
Question 6: When performing an RP assembly test, a tester notices the relief valve is dripping slightly during the No. 1 check test. What does this indicate?
- Check valve #2 has failed and needs replacement
- The relief valve is functioning correctly — it opens when differential pressure drops below 2 psi (Correct answer)
- The supply pressure is too high for the assembly
- The No. 2 shutoff valve was left partially open
Correct answer: The relief valve is functioning correctly — it opens when differential pressure drops below 2 psi
During the No. 1 check test, the tester intentionally lowers differential pressure in the zone; the relief valve opening or dripping at or below 2 psi confirms it is operating as designed.
Question 7: Which of the following backflow assemblies contains an internal air-inlet port that opens to atmosphere during backsiphonage conditions?
- Reduced pressure principle assembly
- Double check valve assembly
- Pressure vacuum breaker (Correct answer)
- Double check detector assembly
Correct answer: Pressure vacuum breaker
The pressure vacuum breaker (ASSE 1020) includes an internally loaded check valve and an air-inlet valve that opens to atmosphere when supply pressure drops, preventing backsiphonage.
BAT Backflow Assembly Tester Prevention Methods 2
Which backflow prevention assembly is the ONLY type approved for use on high-hazard connections to the potable water supply?