FREE Journeyman Plumbers Backflow Prevention Methods Questions and Answers

Question 1

Which backflow prevention method relies on a continuous supply of water and creates an air gap within the device itself to prevent back-siphonage and backpressure?

Accepted Answer

Reduced Pressure Zone (RPZ) assembly

Answer

Double Check (DC) valve assembly

Answer

Atmospheric Vacuum Breaker (AVB)

Answer

Pressure Vacuum Breaker (PVB)

Question 2

A plumber is installing an irrigation system connection to a potable water supply. The local code requires protection against both back-siphonage and backpressure, and the device must be suitable for continuous pressure applications. Which backflow prevention device would be most appropriate?

Accepted Answer

Reduced Pressure Zone (RPZ) assembly

Answer

Hose Bibb Vacuum Breaker (HBVB)

Answer

Air Gap

Answer

Pressure Vacuum Breaker (PVB)

Question 3

Which of the following statements about Atmospheric Vacuum Breakers (AVBs) is FALSE?

Accepted Answer

They are suitable for continuous pressure applications.

Answer

They protect against back-siphonage only.

Answer

They must be installed at least 6 inches above the flood rim level of the fixture served.

Answer

There should be no shut-off valves downstream of the AVB.

Question 4

What is the primary mechanism by which an Air Gap prevents backflow?

Accepted Answer

It creates a physical separation between the potable water outlet and the flood-level rim of the receiving fixture.

Answer

It uses two independently operating check valves.

Answer

It incorporates a relief valve that discharges to the atmosphere.

Answer

It maintains a pressure differential across a diaphragm.

Question 5

A Double Check (DC) valve assembly is typically used in applications where the potential hazard is classified as:

Accepted Answer

Minor hazard (e.g., low-risk potable water connections)

Answer

Severe hazard (e.g., toxic chemicals)

Answer

Moderate hazard (e.g., non-potable water, but not highly toxic)

Answer

No hazard (e.g., direct potable water connections without any risk)

Question 6

Which backflow prevention device requires annual testing and certification by a qualified technician?

Accepted Answer

Pressure Vacuum Breaker (PVB)

Answer

Hose Bibb Vacuum Breaker (HBVB)

Answer

Atmospheric Vacuum Breaker (AVB)

Answer

All types of Air Gaps