FREE Journeyman Plumbers Drainage Waste Venting Questions and Answers

Question 1

A horizontal branch drain serves a total of 20 fixture units (FU). According to common plumbing codes, what is the minimum required diameter for the vent pipe serving this branch?

Accepted Answer

1 1/2 inches

Answer

2 inches

Answer

1 1/4 inches

Answer

3 inches

Question 2

Which of the following is the PRIMARY purpose of a trap seal in a plumbing drainage system?

Accepted Answer

To prevent sewer gases from entering the occupied space

Answer

To provide an access point for drain cleaning

Answer

To regulate the flow rate of wastewater

Answer

To minimize noise from drainage

Question 3

A plumber is installing a fixture trap for a kitchen sink. What is the maximum distance allowed between the trap weir and the vent pipe opening according to most plumbing codes?

Accepted Answer

3 feet 6 inches

Answer

2 feet

Answer

5 feet

Answer

10 feet

Question 4

What is the function of a 'continuous vent' in a drainage waste venting system?

Accepted Answer

It serves as both a drain and a vent for a single fixture.

Answer

It connects multiple fixtures to a single main vent stack.

Answer

It provides a continuous flow of water to prevent blockages.

Answer

It eliminates the need for individual fixture traps.

Question 5

Which of the following conditions would MOST likely lead to the loss of a trap seal due to 'backpressure'?

Accepted Answer

A high-velocity discharge from an upper floor fixture into a partially obstructed stack

Answer

A clogged vent pipe upstream of the trap

Answer

Excessive water flow through the fixture drain

Answer

A long horizontal run of the trap arm

Question 6

When designing a common vent system for two fixtures, which principle must be strictly followed?

Accepted Answer

Each fixture must have its own separate trap.

Answer

The fixtures must be installed at different elevations.

Answer

The common vent must be sized for the combined fixture unit load of both fixtures.

Answer

The common vent must connect directly to the main building drain.

A horizontal branch drain serves a total of 20 fixture units (FU).According to common plumbing codes, what is the minimum required diameter for the vent pipe serving this branch?

A horizontal branch drain serves a total of 20 fixture units (FU).
According to common plumbing codes, what is the minimum required diameter for the vent pipe serving this branch?