Journeyman Plumbers Exam Venting and Backflow Prevention 3

Question 1

An island fixture vent must loop to within how many inches of the underside of the counter?

Accepted Answer

6 inches

Answer

The island fixture vent must loop up to within 6 inches of the underside of the counter top before dropping back to connect to the drain.

Question 2

What is the maximum developed length of a 2-inch vent pipe serving a single water closet?

Accepted Answer

60 feet

Answer

Under the IPC, a 2-inch vent pipe serving a single water closet has a maximum developed length of 60 feet.

Question 3

A pressure vacuum breaker (PVB) differs from an atmospheric vacuum breaker (AVB) in that a PVB:

Accepted Answer

Can be installed under continuous pressure

Answer

A pressure vacuum breaker can remain under continuous supply pressure, whereas an atmospheric vacuum breaker must be de-pressurized for at least 12 hours per day.

Question 4

Where must an air admittance valve (AAV) NOT be installed?

Accepted Answer

Below grade or in a sealed space without air

Answer

AAVs require access to air to function; they cannot be installed below grade or in any sealed space where air is unavailable.

Question 5

Which fixture is permitted to wet vent under most plumbing codes?

Accepted Answer

Bathroom group (lavatory, water closet, tub) on a single floor

Answer

A bathroom group on a single floor is the classic application of wet venting, where the lavatory drain serves as both a drain and a vent for the water closet.

Journeyman Plumbers Exam Practice Test

Journeyman Plumbers Exam Practice Test

Journeyman Plumbers Exam Venting and Backflow Prevention 3