FREE Journeyman Plumbers Drain, Waste, Vent Systems Questions and Answers

Question 1

According to most plumbing codes, what is the maximum allowable distance between cleanouts on a 4-inch horizontal drainage line?

Accepted Answer

100 feet

Answer

50 feet

Answer

75 feet

Answer

150 feet

Question 2

A plumber is installing a wet vent for a single bathroom group. Which of the following is a universal requirement for this type of installation?

Accepted Answer

All fixtures served by the wet vent must be on the same floor level.

Answer

The wet-vented section must be two pipe sizes larger than the minimum required drain size.

Answer

The toilet must be the last fixture connected to the horizontal wet vent.

Answer

A maximum of four fixtures can be served by the wet vent.

Question 3

What is the minimum required clearance in front of a cleanout for a 3-inch drain pipe to allow for proper rodding and servicing?

Accepted Answer

18 inches

Answer

12 inches

Answer

24 inches

Answer

36 inches

Question 4

A residential bathroom group consists of a standard water closet (1.6 GPF), a lavatory, and a bathtub. What is the total Drainage Fixture Unit (DFU) load for this group that should be used for sizing the branch drain?

Accepted Answer

6 DFU

Answer

5 DFU

Answer

7 DFU

Answer

8 DFU

Question 5

Which of the following describes the minimum required length for a trap arm, as measured from the trap weir to the inner edge of the vent?

Accepted Answer

It must be at least two times the diameter of the trap arm.

Answer

It must be equal to the diameter of the trap arm.

Answer

It must be at least 12 inches long.

Answer

It must not exceed the diameter of the trap arm.

Question 6

A plumber needs to connect a horizontal branch drain to a vertical stack. To ensure proper flow and prevent blockages, which type of fitting is most appropriate for this connection?

Accepted Answer

A combination wye and 1/8 bend or a long sweep fitting

Answer

A sanitary tee

Answer

A vent tee

Answer

A short sweep 90-degree elbow