Grease Trap Sizing Calculator

What size grease trap do I need?

The Grease Trap Sizing calculator accurately sizes passive grease traps, grease interceptors, and automated grease recovery devices (GRD) for restaurant kitchens & foodservice facilities.

Passive Grease traps store and accumulate the fat, oil, grease, (FOG) and food solids until the grease trap is pumped out. Passive Grease Traps require time for the FOG to separate and settle from the wastewater (detention time). Automatic Dishwashers are not attached to a grease trap as the high volume wastewater outflow will bypass the grease trap. It is important to size a grease trap larger than calculated (round up to next available size only). A grease interceptor that is extremely oversized will have longer periods between pump-outs. The rotting grease will adversely affect the structure of the grease interceptor.

A Grease Recovery Device (Goslyn) separates the FOG from the wastewater as it enters the device. Goslyn controls the inflow of effluent or wastewater. Wastewater with a high flow rate (automatic dishwasher) will not bypass a Goslyn GRD. A 3-compartment sink will only have a longer drainage time period if the Grease Recovery Device is undersized.

Automatic dishwashers attach to Goslyn Grease Recovery Devices. Automatic dishwashers do not attach to passive Grease traps. The GPM of an automatic dishwasher is not included in Grease Recovery Device and Grease Trap sizing formulas.

STEP #1. ENTER COMPARTMENT SINK MEASUREMENTS
		ENTER COMPARTMENT SINK MEASUREMENTS IN INCHES			231 Cubic Inches in 1 US Gallon
Sinks Measured in Inches		Length	Width	Depth	Cubic Capacity	Volume In US gallons
Sink # 1
Compartment 1
Compartment 2
Compartment 3
Compartment Sink # 1 - Totals						Gallons
Sink # 2
Compartment-1
Compartment-2
Compartment-3
Compartment Sink # 2 - Totals						Gallons
Maximum Discharge (2 Sinks Combined)						Gallons
Drainage Load - 75% of Maximum Discharge (Dishes Displace 25% of the water in sink)						Gallons

 

STEP #2. ENTER ADDITIONAL APPLIANCES
Enter Appliances			Appliance # 1				GPM
Including			Appliance # 2				GPM
Rotisserie, Wok,			Appliance # 3				GPM
Combi-Oven, Slop Sink			Total Additional Discharge				GPM

 

STEP #3. VIEW REQUIREMENTS					Total Gallons Per Minutes
			Actual Drainage Load				GPM

	Goslyn Grease Recovery Devices
Goslyn Facility Use			Goslyn Drain Times in Minutes
QSR or Combi-Oven			GOS-40 Drainage Time				Minutes
Restaurant Unit			GOS-60LP Drainage Time				Minutes
Restaurant Unit or Cafeteria or Golf Course			GOS-80 Drainage Time				Minutes
Faster Drainage Times Require a Larger Goslyn
Goslyn Grease Recovery Device Measurements Link
	1 US Gallon = 3.78541178 Litres

Passive Conventional Grease Trap Required								GPM
Grease Trap Sizes (GPM)				10	15	20	25	35	50
Grease Trap Weights (LBS)				20	30	40	50	70	100
"2BIG" Means that you require a passive grease trap greater than 50 GPM
Standard Grease Trap Sizes Range from 15 - 50 GPM

Draining Period of 3-Compartment Sink Applies to Passive Grease Traps Only							Minute
Actual Drainage Load in Gallons Per Minute (GPM)							GPM

Grease Trap Sizing (Hydro Mechanical)

2 or 3 Compartment sink Cubic Capacity = width x length x depth (in inches)

Volume in Gallons = Cubic Capacity / 231

1 US Gallon = 231 cubic inches (volume)

Remember: Hydro Mechanical Interceptors are Measured By FLOW (GPM)

Grease Interceptor Sizing (Gravity)

GPM for an In-ground Grease Interceptor is multiplied by a factor of 30 (minutes) to accomodate settling of food solids and hardening of animal fats (retention time)

In-Ground Grease Interceptor (Gallons) = Calculated GPM X 30
(30 Minutes retention time as suggested by the Plumbing and Drainage Institute)

Remember: Gravity Interceptors are Measured By VOLUME (GALLONS)