Master Plumber Exam Drain, Waste, & Vent Systems 3

Question 1

Which material is NOT permitted for underground drain piping inside a building per the IPC?

Accepted Answer

Galvanized steel

Answer

Galvanized steel is not listed by the IPC as an approved material for underground drain, waste, and vent piping due to corrosion susceptibility.

Question 2

What is the maximum number of fixture units that can drain into a 4-inch horizontal branch drain?

Accepted Answer

216 fixture units

Answer

Per IPC drainage fixture unit tables, a 4-inch horizontal branch drain can handle a maximum of 216 fixture units.

Question 3

An air admittance valve (AAV) may NOT be used as the sole vent for which application under the IPC?

Accepted Answer

The main stack vent termination to outside air

Answer

At least one vent in every building must extend to open outdoor air; an AAV cannot replace the required outdoor vent termination for the entire building's DWV system.

Question 4

What is the minimum diameter for a building sewer serving a single-family home with up to 21 drainage fixture units?

Accepted Answer

4 inches

Answer

The IPC requires a minimum 4-inch building sewer for a single-family dwelling regardless of the calculated fixture unit load.

Question 5

A sanitary tee fitting may be used in which orientation for drain connections?

Accepted Answer

Upright with flow entering from the side branch vertically downward

Answer

A sanitary tee is approved only in the upright position where the branch enters from the side and flow descends into the vertical leg, not laid on its back for horizontal connections.

Master Plumber Exam Practice Test

Master Plumber Exam Practice Test

Master Plumber Exam Drain, Waste, & Vent Systems 3