Master Plumber Exam Plumbing Codes and Regulations 2 — Questions and Answers
Question 1: Under the UPC, what is the minimum trap seal depth required for fixture traps?
- 1 inch
- 2 inches (Correct answer)
- 3 inches
- 4 inches
Correct answer: 2 inches
The UPC requires a minimum trap seal depth of 2 inches to prevent sewer gases from entering the building.
Question 2: According to the IPC, what is the maximum developed length for a fixture drain from the trap weir to the vent connection?
- 2 feet
- 4 feet
- 6 feet
- 8 feet (Correct answer)
Correct answer: 8 feet
The IPC allows a maximum developed length of 8 feet from the trap weir to the vent for most fixtures.
Question 3: Which code body publishes the Uniform Plumbing Code (UPC)?
- ICC
- IAPMO (Correct answer)
- ASME
- NFPA
Correct answer: IAPMO
The International Association of Plumbing and Mechanical Officials (IAPMO) publishes and maintains the UPC.
Question 4: Under the IPC, a 3-inch horizontal drain serving a water closet must have a minimum slope of:
- 1/16 inch per foot
- 1/8 inch per foot
- 1/4 inch per foot (Correct answer)
- 1/2 inch per foot
Correct answer: 1/4 inch per foot
The IPC requires 3-inch and larger horizontal drains to slope at a minimum of 1/4 inch per foot toward the outlet.
Question 5: Which of the following materials is NOT permitted for gas supply piping under most model plumbing codes?
- CSST
- Schedule 40 black steel pipe
- Type K copper
- PVC (Correct answer)
Correct answer: PVC
PVC is not approved for gas supply piping because it is combustible and cannot withstand gas pressure and heat requirements.
Question 6: The IPC requires cleanouts to be installed at the base of each stack and at intervals not exceeding:
- 50 feet
- 75 feet
- 100 feet (Correct answer)
- 150 feet
Correct answer: 100 feet
The IPC requires cleanouts at the base of each stack and at maximum 100-foot horizontal intervals.
Question 7: Under model plumbing codes, what is the required minimum hot water temperature at the source to prevent Legionella growth?
- 110°F
- 120°F
- 130°F
- 140°F (Correct answer)
Correct answer: 140°F
Plumbing codes and ASHRAE 188 recommend storing domestic hot water at 140°F to inhibit Legionella bacteria growth.
Master Plumber Exam Plumbing Codes and Regulations 2
Under the UPC, what is the minimum trap seal depth required for fixture traps?