Master Plumber Exam Plumbing Codes and Regulations 3 — Questions and Answers
Question 1: Per the IPC, which type of vent is defined as a vent that connects directly to the drain between the trap and the trap arm?
- Common vent
- Wet vent (Correct answer)
- Air admittance valve
- Loop vent
Correct answer: Wet vent
A wet vent serves as both a drain and a vent simultaneously, connecting within the zone between trap and trap arm.
Question 2: According to the IPC, the maximum distance between a water closet trap and its vent is:
- 2 feet
- 4 feet
- 6 feet
- 10 feet (Correct answer)
Correct answer: 10 feet
The IPC allows a trap-to-vent distance of up to 10 feet for a 3-inch water closet drain.
Question 3: Under the UPC, copper tubing used for water distribution inside a building must be at minimum which type?
- Type M (Correct answer)
- Type L
- Type K
- Type DWV
Correct answer: Type M
The UPC allows Type M copper (thinnest wall) for most interior water supply piping in residential applications.
Question 4: A plumber installs a new lavatory in a commercial building. The IPC requires the drain outlet to be a minimum of:
- 1-1/4 inches (Correct answer)
- 1-1/2 inches
- 2 inches
- 3 inches
Correct answer: 1-1/4 inches
The IPC specifies that lavatory fixture drain outlets must be a minimum of 1-1/4 inches in diameter.
Question 5: Which ASSE standard governs the performance requirements for pressure-balancing shower valves?
- ASSE 1002
- ASSE 1016 (Correct answer)
- ASSE 1070
- ASSE 1082
Correct answer: ASSE 1016
ASSE 1016 covers the performance requirements for automatic compensating shower and tub/shower mixing valves.
Question 6: Under the IPC, indirect waste piping from a commercial dishwasher must discharge to a floor sink with a minimum air gap of:
- 1/2 inch
- 1 inch
- 2 pipe diameters
- 1 inch or 2 pipe diameters, whichever is greater (Correct answer)
Correct answer: 1 inch or 2 pipe diameters, whichever is greater
The IPC requires an indirect waste air gap of 1 inch or 2 pipe diameters above the flood rim, whichever is greater.
Question 7: Per the IPC, a building sewer serving a building with 50 drainage fixture units must be at least:
- 3 inches
- 4 inches (Correct answer)
- 5 inches
- 6 inches
Correct answer: 4 inches
A 4-inch building sewer can handle up to 216 drainage fixture units under IPC sizing tables.
Master Plumber Exam Plumbing Codes and Regulations 3
Per the IPC, which type of vent is defined as a vent that connects directly to the drain between the trap and the trap arm?