Backflow Prevention Assembly Tester — Practice Exam
Protection: practice questions
Our Backflow Tester bank has 9 questions on this topic. Here are 3 of them with answers; the full mock exam draws from every topic, like the real one.
Question 1
What is the main limitation of an air gap in a pressurized system?
- It can't be inspected
- It costs more than an RP to install
- Pressure is lost, so a pump or tank may be needed downstream
- It allows backpressure from the receiving tank to reach the supply
Show the answer
C. Pressure is lost, so a pump or tank may be needed downstream — Water falls to atmospheric pressure at the gap.
Question 2
Why might a purveyor require containment even when internal protection exists?
- Containment is cheaper
- Containment is always cheaper than internal protection
- Internal devices can be removed or bypassed, so the public supply still needs protection
- Internal protection is never allowed by plumbing codes, so containment replaces it
Show the answer
C. Internal devices can be removed or bypassed, so the public supply still needs protection — Defense in depth.
Question 3
What is the minimum air gap for a 1/2-inch outlet?
- 0.25 inch
- 0.5 inch
- 1 inch
- 2 inches
Show the answer
C. 1 inch — 2 × 0.5 = 1 inch, which equals the minimum.