Journeyman Plumber ExamPlumbing Code and RegulationsHard
A plumber is performing a final inspection of a newly installed commercial kitchen. The kitchen includes multiple grease-producing fixtures. According to the Uniform Plumbing Code (UPC), what is the minimum required size for the outlet pipe of a grease interceptor serving a commercial kitchen?
- A4 inches (100 mm)
- B2 inches (50 mm)
- C3 inches (75 mm)
- DThe same size as the inlet pipe, but not less than 2 inches.
Show answer & explanationAnswer & explanation
Correct answer: D. The same size as the inlet pipe, but not less than 2 inches.
The UPC typically requires the outlet pipe of a grease interceptor to be the same size as the inlet pipe, but not less than 2 inches, to maintain proper flow and prevent blockages. The size is determined by the fixture units it serves.
Why the other options are wrong
- A. 4 inches is used for larger installations, but not a general minimum or rule.
- B. While 2 inches is a minimum, the outlet must match the inlet, which could be larger.
- C. 3 inches is a common size, but not a universal minimum or requirement to match the inlet.
Grease Interceptor Outlet Sizing
The determination of the correct diameter for the discharge pipe of a grease interceptor to ensure efficient flow and prevent blockages, as specified by plumbing codes.
- Typically matches the inlet pipe size.
- Minimum size often specified (e.g., 2 inches).
- Sizing calculations are based on fixture units or flow rates.
Memory trick: Inlet-Outlet Match, No Grease Catch!