A full-service restaurant kitchen case study — which fixtures must (and must not) connect to a grease interceptor, a worked sizing cross-check between the hydromechanical and gravity methods, indoor-vs-outdoor interceptor type selection, and the maintenance program that keeps a correctly sized interceptor from failing anyway.
The project brief: a restaurant's commercial kitchen has a three-compartment pot/prep sink, a two-compartment prep sink, and two pre-rinse spray stations ahead of a conveyor dish machine. This module applies Module 11's fats-oils-and-grease methodology to a real kitchen rather than a single textbook fixture — identifying exactly which fixtures connect to the grease interceptor and which must be kept off it, then sizing the interceptor against the kitchen's actual fixture load.
Running the kitchen's fixture volumes through the PDI G101 flow-rate method rules out an indoor hydromechanical interceptor outright, before the design ever gets to an outdoor gravity tank's own retention-time calculation, location, venting, and inspection access — plus the 25%-rule maintenance program that keeps the whole system compliant after handover. The full worked numbers, complete bill of materials, and finished design reasoning are part of the unlocked module below.