BAT Backflow Assembly Field Testing Procedures 2 — Questions and Answers
Question 1: During normal operation, a dripping relief valve on an RPZ assembly most likely indicates:
- The assembly is functioning correctly under high supply pressure
- Check valve #1 is failing to maintain adequate differential pressure (Correct answer)
- The downstream demand is exceeding system capacity
- The supply pressure is below the minimum operating pressure
Correct answer: Check valve #1 is failing to maintain adequate differential pressure
A dripping relief valve during normal operation typically means check valve #1 is fouled or not seating, causing zone pressure to rise until the relief valve cracks open.
Question 2: Which condition would cause an RPZ assembly to FAIL a field test?
- Check valve #1 holds 6.0 psi differential
- Check valve #2 holds 2.0 psi differential
- The relief valve fails to open when zone pressure equals supply pressure (Correct answer)
- The relief valve opens when zone pressure is 2.5 psi below supply pressure
Correct answer: The relief valve fails to open when zone pressure equals supply pressure
The relief valve must open when zone pressure equals supply pressure; failure to open means the assembly cannot provide backpressure backflow protection.
Question 3: To test check valve #2 on a Double Check Valve Assembly, the correct procedure is to:
- Open the #1 shutoff valve and observe pressure at test cock #3
- Close the #2 shutoff valve, bleed downstream pressure, then measure differential across check valve #2 via test cocks #2 and #3 (Correct answer)
- Remove and bench test check valve #2 separately
- Pressurize the downstream side and measure the pressure drop across the assembly
Correct answer: Close the #2 shutoff valve, bleed downstream pressure, then measure differential across check valve #2 via test cocks #2 and #3
Closing the #2 shutoff valve, bleeding off downstream pressure, then reading the differential across test cocks #2 and #3 isolates and measures check valve #2's holding capacity.
Question 4: Which ASSE standard governs the performance and testing requirements for RPZ assemblies?
- ASSE 1013 (Correct answer)
- ASSE 1015
- ASSE 1019
- ASSE 1047
Correct answer: ASSE 1013
ASSE 1013 covers Reduced Pressure Principle Backflow Preventers, establishing performance requirements including those used in field testing evaluation.
Question 5: At what minimum differential pressure should the air inlet valve on a Pressure Vacuum Breaker (PVB) open during a field test?
- 0.5 psi
- 1.0 psi (Correct answer)
- 2.0 psi
- 3.5 psi
Correct answer: 1.0 psi
Per ASSE 1020, the air inlet valve on a PVB must open at a differential of at least 1.0 psi to admit air and break a potential siphon.
Question 6: What does a 'bouncing' or oscillating needle on a differential pressure gauge indicate during a backflow field test?
- The check valve is holding properly under pressure
- Fluctuating or unstable supply pressure in the system (Correct answer)
- The test kit gauge is properly calibrated
- A tight shutoff valve upstream of the assembly
Correct answer: Fluctuating or unstable supply pressure in the system
A bouncing gauge needle indicates fluctuating supply pressure, which makes reliable differential readings difficult and may require the tester to investigate the cause before proceeding.
Question 7: Which backflow prevention assembly type has a relief valve that vents the intermediate zone pressure to atmosphere when zone pressure rises to supply pressure?
- Double Check Valve Assembly (DCVA)
- Pressure Vacuum Breaker (PVB)
- Reduced Pressure Zone Assembly (RPZ) (Correct answer)
- Spill-Resistant Vacuum Breaker (SVB)
Correct answer: Reduced Pressure Zone Assembly (RPZ)
The RPZ assembly has a differential pressure relief valve that opens and discharges to atmosphere whenever zone pressure equals or exceeds supply pressure, providing the highest protection level.
BAT Backflow Assembly Field Testing Procedures 2
During normal operation, a dripping relief valve on an RPZ assembly most likely indicates: