Sizing for Commercial Sinks


The separator should hold one half of the liquid holding capacity of the sink that it services. To determine the cubic holding capacity of the sink, multiply the Length by the Width by the Depth in inches. Divide this figure by 231 to obtain the liquid holding capacity in Gallons. (Example shown is a single compartment sink. Multiply by the number of compartments to get the total holding capacity.) Use this figure in the chart.


L” x W” x D”


24″ x 24″ x 20″ =11,520 cu in = 49.87 Gal

Use G-2420 or G-36-LO.

G Series are used for on-the-floor installation. Use GF Series if a flush-with-floor installation is required.

*Low-Inlet models are recommended when a quick opening drain valve is used on the sink waste, resulting in a low waste outlet from the sink. Use a Low-Inlet model when there is not sufficient room next to the sink, or when it is necessary to place the separator underneath the sink drainboard. On larger model separators, we recommend a flush-with-floor installation in concrete floor construction. For installations in or on the floor below, use the next larger size separator.


Type of Fixture: 2-Compartment Commercial Sink
Maximum Holding Capacity of Fixture: 30 gallons
Liquid Holding Capacity and Seal of Separator: 17 gallons
Separator Model: G-1820


Number of Fixtures: 3-5
Maximum Holding Capacity of Fixture: 110 gallons
Liquid Holding Capacity and Seal of Separator: 60 gallons
Separator Model: G-3050
Location: Floor below fixtures


A grinder with a 1/2 h.p. motor requires a separator with a minimum holding capacity of 50 gallons. This is for a small installation in a restaurant with a seating capacity up to 100 people. For larger grinders with higher h.p. ratings, each additional 1/2 h.p. requires an increase of 20 gallons to the separator. Thus, a 1 h.p. grinder requires a 70 gallon holding capacity, a 1 1/2 h.p. grinder requires a 90 gallon holding capacity, and so on.


Select a separator with a holding capacity equal to one hour’s water consumption. On a dishwasher with three tanks, bypass the final rinse when permitted by code. If the rinse water bypasses the separator, the liquid holding capacity of the separator shall be equal to or greater than the total liquid holding capacity of the dishwasher.