Backflow Tester Exam Questions & Answers 2026 (11–20)

Question 1

During RPZ testing, if the No. 2 check valve is found to be 'closed tight', the tester should record it as:

TheoryPractice · Accepted Answer

Pass — a closed tight check is acceptable. A 'closed tight' No. 2 check valve reading (needle does not move) is recorded as a pass because the check is holding and not allowing reverse flow; tight closure is acceptable and desirable.

Question 2

During an RPZ test, you needle the No. 1 check and observe the differential gauge drop to 1.8 psid at which point the relief valve opens. What is the correct test result interpretation?

TheoryPractice · Accepted Answer

Fail — check #1 must hold at least 2.0 psid before relief opens, indicating inadequate differential. The RPZ relief valve is supposed to open at 2.0 psid below supply. If the gauge shows 1.8 psid when the relief cracks open, check #1 is not maintaining the required 2.0 psid differential. The first check fails its minimum differential requirement.

Question 3

The minimum differential pressure at which either check valve of a Double Check Valve Assembly (DCVA) must hold to pass a field test is:

TheoryPractice · Accepted Answer

1.0 psid. Both check valves in a DCVA must maintain a differential pressure of at least 1.0 psid during field testing. This threshold confirms the spring-loaded check is seating properly and providing measurable resistance.

Question 4

When testing a DCVA, if check valve No. 2 reads 'closed tight' with no gauge movement, the correct interpretation is:

TheoryPractice · Accepted Answer

Pass — closed tight is acceptable for No. 2 check. A 'closed tight' reading on DCVA check No. 2 indicates the check is fully seating and holding the pressure differential without any leak. This is an acceptable passing condition for the second check valve.

Question 5

A DCVA is installed on a fire sprinkler service. During testing, check No. 1 reads 0.8 psid before the gauge stabilizes. What is the proper action?

TheoryPractice · Accepted Answer

Record as fail and report to the authority having jurisdiction (AHJ); do not repair without authorization. A reading below the 1.0 psid minimum is a failing result. The tester records the fail and notifies the AHJ; unauthorized on-the-spot repair (especially on a fire sprinkler service) may violate procedures and require AHJ approval before the system is returned to service.

Question 6

During a PVB field test, the air inlet valve must open at a supply pressure no greater than:

TheoryPractice · Accepted Answer

1.0 psid. The air inlet (poppet) on a PVB must open at 1.0 psid or less as supply pressure is bled down. If the inlet does not open by the time differential drops to 1.0 psi the assembly fails because it would not protect under mild vacuum conditions.

Question 7

The check valve inside a PVB assembly must hold a minimum differential of:

TheoryPractice · Accepted Answer

1.0 psid. The internal check valve of a PVB must maintain at least 1.0 psid during the field test, confirming it seats properly and provides the primary barrier against reverse flow under normal operating pressure.

Question 8

While testing a PVB, you open test cock No. 2 slowly and the air inlet immediately cracks open before you even begin to lower supply pressure. What does this indicate?

TheoryPractice · Accepted Answer

The check valve is leaking, causing downstream pressure to drop and prematurely open the air inlet. If the air inlet opens immediately upon cracking test cock No. 2, the check valve downstream of the air inlet is probably fouled or leaking, allowing a pressure drop that mimics back-siphonage. This points to a failing check valve.

Question 9

A Spill-Resistant Pressure Vacuum Breaker (SRPVB) differs from a standard PVB primarily because it:

TheoryPractice · Accepted Answer

Contains an elastomeric diaphragm that prevents spillage when pressure fluctuates. An SRPVB incorporates a sealed, spring-loaded poppet inside a pressurized body so that minor pressure fluctuations do not cause the air inlet to spill water. It still protects only against back-siphonage, not backpressure.

Question 10

Can a Spill-Resistant PVB (SRPVB) be installed where backpressure conditions may exist?

TheoryPractice · Accepted Answer

No, an SRPVB only protects against back-siphonage, not backpressure. Despite its sealed body, an SRPVB is approved only for back-siphonage conditions. Under true backpressure the internal poppet can be forced open from downstream, allowing contamination to enter the supply. An RPZ or DCVA is required for backpressure hazards.

Backflow Tester Exam Questions & Answers 2026 (11–20)

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