Journeyman Plumber ExamDrainage, Waste, and Venting (DWV) SystemsEasy
A plumber is installing a floor drain in a commercial kitchen. The drain is subject to heavy grease and oil discharge. Which of the following is REQUIRED to be installed upstream of this floor drain?
- AGrease interceptor
- BBackwater valve
- CSediment trap
- DAir gap
Show answer & explanationAnswer & explanation
Correct answer: A. Grease interceptor
Any fixture that is likely to discharge grease or oil, such as a floor drain in a commercial kitchen, must be connected to a grease interceptor to prevent these substances from entering and clogging the public sewer system.
Why the other options are wrong
- B. A backwater valve prevents sewage from backing up into the building, but does not address grease.
- C. A sediment trap is used to collect solid debris, not grease, and is typically found on water heaters.
- D. An air gap prevents backflow contamination of potable water and is not relevant to grease separation.
Grease Interceptor Requirement
A plumbing device required for commercial establishments that discharge significant amounts of grease and oils into the drainage system, preventing blockages in public sewers.
- Required for commercial kitchens, food processing.
- Separates fats, oils, and grease (FOG).
- Must be regularly maintained and cleaned.
Memory trick: Grease in the drain, intercept the pain.