Grease Interceptor Flow Capacity
The peak fixture flow an existing grease interceptor is rated to serve.
Example
You enter
- Interceptor volume (gal) 1000
- Retention time (min) 30
- Loading factor 1.25
You get
- Peak flow served 26.7 gpm
Checked against published worked examples from: PDI.
Details, formula, and sources
Scopepeak flow = volume / (retention x loading). A 1,000-gal interceptor at 30 min retention and 1.25 loading serves ~26.7 gpm; compare to the connected sinks' DFU flow to check for undersizing (PDI G101 / IPC). AHJ governs.
Formula or tablepeak_flow_gpm = interceptor_volume_gal / (retention_minutes × loading_factor), the PDI G101 / IPC sizing relation Volume = peak GPM × retention × loading solved for the flow.
Source and editionPDI G101 by name; IPC 2027 (International Plumbing Code). Section 1003.
Free accessFree read-only access at codes.iccsafe.org. PDI G101 licensed; manufacturer (Schier, Thermaco, Rockford) sizing tools free.
What governsEstimate. AHJ and licensed plumber / gas fitter govern. Verify against the IPC / IFGC edition adopted in your jurisdiction.
API field namesinterceptor_volume_gal, retention_minutes, loading_factor, peak_flow_gpm
- Retention time 30 min unless user suppliesPDI G101 by name
- Loading factor 1.25 unless user supplies adjustment for high-grease useengineering practice