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Installation practice questions

22 questions from the backflow prevention tester practice test.

Installation practice test

10 questions, graded as you go, with the reason for every answer. No sign-up.

What this covers

Sample questions

How high must an atmospheric vacuum breaker be installed?

  1. At least 6 inches below the lowest downstream piping or outlet it serves
  2. At least 12 inches above the finished grade or floor level
  3. At least 6 inches above the highest downstream piping or outlet
  4. At the same level as the highest downstream outlet it serves
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C. At least 6 inches above the highest downstream piping or outlet

The AVB must sit at least 6 inches above all downstream piping and the flood rim of what it serves, so no water stands above it to cause backpressure. Height above the floor is not the controlling measurement.

Reference: ASSE 1001; EPA Cross-Connection Control Manual (EPA 816-R-03-002), ch. 4

A pressure vacuum breaker serving an irrigation system is normally installed at what height?

  1. At least 6 inches below the lowest downstream piping or sprinkler head
  2. At least 12 inches above the highest downstream piping or sprinkler head
  3. At least 12 inches below grade in a valve box with a gravel base
  4. At any height, provided the downstream piping slopes back to it
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B. At least 12 inches above the highest downstream piping or sprinkler head

A PVB goes at least 12 inches above the highest downstream piping or outlet so the downstream water cannot place backpressure on it. Installing it in a box below grade would also let the air inlet flood.

Reference: ASSE 1020; EPA Cross-Connection Control Manual (EPA 816-R-03-002), ch. 4

How should the relief valve discharge of an RP assembly be connected to a drain?

  1. With a solid pipe connection sealed into the drain line
  2. Through an air gap between the relief opening and the drain
  3. Through a trap that is primed from the relief opening
  4. With a hose clamped to the relief opening and run to a sewer
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B. Through an air gap between the relief opening and the drain

The relief port must discharge through an air gap, usually an air gap fitting or funnel, so a blocked or backed-up drain cannot reach the assembly. A solid connection would turn the relief port into a cross-connection with the drain.

Reference: AWWA Manual M14, Backflow Prevention and Cross-Connection Control, installation; manufacturer instructions

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