Master Plumber Exam Plumbing Codes and Regulations 4 — Questions and Answers
Question 1: Under the IPC, what is the required test pressure for a new water distribution system before it is put into service?
- 50 psi for 15 minutes
- 100 psi for 15 minutes (Correct answer)
- 125 psi for 2 hours
- 150 psi for 30 minutes
Correct answer: 100 psi for 15 minutes
The IPC requires new water distribution systems to be tested at 100 psi for a minimum of 15 minutes without leakage.
Question 2: Which code section of the IPC specifically governs storm drainage systems?
- Chapter 7
- Chapter 10 (Correct answer)
- Chapter 11
- Chapter 12
Correct answer: Chapter 10
IPC Chapter 10 covers storm drainage, including roof drains, leaders, and storm sewer connections.
Question 3: According to the IPC, a floor drain installed in a parking garage must be connected to:
- The sanitary sewer directly
- A sand/oil interceptor before the sewer (Correct answer)
- A grease interceptor
- A sump pump only
Correct answer: A sand/oil interceptor before the sewer
Parking garage floor drains must discharge through a sand and oil interceptor to remove petroleum products before entering the sewer.
Question 4: Under model plumbing codes, what is the minimum number of fixture units a 4-inch vertical soil stack can carry?
- 48 DFU
- 96 DFU
- 256 DFU (Correct answer)
- 500 DFU
Correct answer: 256 DFU
Per IPC Table 710.1, a 4-inch vertical stack can carry 256 drainage fixture units.
Question 5: The IPC requires that vent pipes penetrating a roof extend a minimum of how far above the roof surface in areas subject to frost?
- 2 inches
- 6 inches
- 12 inches (Correct answer)
- 6 inches above the anticipated snow depth
Correct answer: 12 inches
In frost areas the IPC requires vent terminals to extend at least 12 inches above the roof to prevent frost closure.
Question 6: Per OSHA and plumbing codes, a plumber working in a trench deeper than 5 feet must ensure the trench is:
- Inspected weekly
- Sloped, shored, or shielded (Correct answer)
- Covered with steel plates at night
- At least 3 feet wide
Correct answer: Sloped, shored, or shielded
OSHA 29 CFR 1926.652 requires trenches 5 feet or deeper to be sloped, shored, or protected with a trench shield.
Question 7: Which of the following fixtures does NOT require a trap under model plumbing codes?
- Floor drain
- Laundry tub
- Water closet (Correct answer)
- Shower
Correct answer: Water closet
Water closets have an integral trap built into the bowl and do not require a separate external trap.
Master Plumber Exam Plumbing Codes and Regulations 4
Under the IPC, what is the required test pressure for a new water distribution system before it is put into service?