FREE Master Plumber Plumbing Code & Regulations Questions and Answers

Question 1

According to most international plumbing codes, what is the minimum required air gap for a water supply outlet above the flood level rim of a lavatory?

Accepted Answer

1.5 inches (38 mm)

Answer

1 inch (25 mm)

Answer

2 inches (51 mm)

Answer

0.5 inches (13 mm)

Question 2

A master plumber is installing a new commercial kitchen. Which of the following drainage fixture units (DFU) is typically assigned to a floor drain with an indirect waste receptor, assuming standard code requirements?

Accepted Answer

2 DFU

Answer

3 DFU

Answer

4 DFU

Answer

1 DFU

Question 3

During an inspection of a newly installed water heater, the inspector notes that the temperature and pressure (T&P) relief valve discharge pipe terminates directly into the building's main drainage system without an air gap. What is the most significant code violation in this scenario?

Accepted Answer

The discharge pipe must terminate to an indirect waste receptor or outside the building with an air gap.

Answer

The discharge pipe should be insulated.

Answer

The discharge pipe diameter is incorrect.

Answer

The T&P valve is installed in the wrong location.

Question 4

What is the primary purpose of a 'trap seal primer' in a plumbing drainage system?

Accepted Answer

To prevent sewer gases from entering a building through floor drains.

Answer

To increase water pressure in the system.

Answer

To reduce the noise of water flowing through pipes.

Answer

To automatically shut off water in case of a leak.

Question 5

A plumbing project involves installing a new backflow prevention device on a cross-connection deemed a 'severe hazard.' Which type of backflow preventer is generally required for such an application, according to common plumbing codes?

Accepted Answer

Reduced Pressure Principle (RPZ) backflow preventer

Answer

Pressure Vacuum Breaker (PVB)

Answer

Double Check Valve Assembly (DCVA)

Answer

Atmospheric Vacuum Breaker (AVB)

Question 6

According to UPC and IPC, what is the maximum permissible developed length for a trap arm, measured from the weir of the trap to the vent fitting, for a 1 1/2-inch fixture drain?

Accepted Answer

2 feet 6 inches (762 mm)

Answer

3 feet 6 inches (1067 mm)

Answer

5 feet 0 inches (1524 mm)

Answer

4 feet 0 inches (1219 mm)