Journeyman Plumbers Exam Backflow Prevention 3

Question 1

An RPZ assembly must be installed how far above the floor or ground to allow for drainage and testing?

Accepted Answer

At least 12 inches

Answer

RPZ assemblies require a minimum of 12 inches of clearance above the floor to allow access for testing and to permit relief port drainage.

Question 2

Which backflow device is NOT acceptable for use under continuous supply pressure?

Accepted Answer

Atmospheric vacuum breaker (AVB)

Answer

Atmospheric vacuum breakers must not be subjected to continuous supply pressure exceeding 12 hours as it can hold the check open, defeating the device.

Question 3

What does the relief port on an RPZ assembly do during a backflow event?

Accepted Answer

It opens to discharge water and protect the supply line from contamination

Answer

When the differential pressure drops below 2 psi, the relief valve opens to atmosphere, discharging water rather than allowing contaminated water to reach the supply.

Question 4

A plumber is installing a backflow preventer on a chemical injection system for a swimming pool. Which device is required?

Accepted Answer

Reduced pressure zone assembly

Answer

Chemical injection systems represent a severe health hazard and require an RPZ assembly for the highest level of protection.

Question 5

How often must a testable backflow prevention assembly be tested after installation?

Accepted Answer

Annually

Answer

Most jurisdictions following the USC model require testable backflow prevention assemblies to be tested annually by a certified tester.

Journeyman Plumbers Exam Practice Test

Journeyman Plumbers Exam Practice Test

Journeyman Plumbers Exam Backflow Prevention 3