Master Plumber Exam Backflow Prevention and Safety 3

Question 1

An RPZ assembly relief valve is discharging water continuously during normal system operation. What is the most likely cause?

Accepted Answer

Inlet pressure is too low

Answer

If the first check valve fails to hold, the pressure in the zone drops below the inlet, causing the relief valve to open and discharge water continuously.

Question 2

Which backflow prevention method provides the highest level of protection for a potable water supply?

Accepted Answer

Air gap

Answer

An air gap is the only backflow prevention method that provides a complete physical separation between the supply and potential contaminant, making it the most reliable protection.

Question 3

Under ASSE 1013, what is the minimum relief valve opening differential pressure for a reduced pressure zone assembly?

Accepted Answer

2 psi

Answer

ASSE 1013 requires the RPZ relief valve to open when the differential pressure across the first check drops to 2 psi or less, protecting the zone.

Question 4

A booster pump on a recirculating fire suppression system is connected to the potable water main. Which device is required at the connection?

Accepted Answer

Double check detector assembly (DCDA)

Answer

Fire suppression systems with pumps represent a potential backpressure hazard requiring a double check detector assembly to protect the potable supply.

Question 5

How often must testable backflow prevention assemblies typically be tested after initial installation under most US jurisdictions?

Accepted Answer

Annually

Answer

Most US jurisdictions require annual testing of all testable backflow prevention assemblies (RPZ, DCVA, PVB) by a certified tester.

Master Plumber Exam Practice Test

Master Plumber Exam Practice Test

Master Plumber Exam Backflow Prevention and Safety 3