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The Grease Trap Basics

August 12, 2019

Also known as a grease interceptor, the grease trap is a receptacle installed between the restaurant drain lines and the sanitary sewer lines. This piece of equipment will  prevent  fats, oils and greases from entering the sewer systems. It does so by separating those items from the used water. School and large food establishments utilize larger model grease traps and install them outside. Smaller models are all interior.

Many towns require the use of grease traps knowing that these fats, oils and greases can impair municipal wastewater systems. Although, a minimal amount of these impurities may be acceptable in the water exiting your drains, many cities and towns will impose a fine for exceeding their acceptable limits. 

How do Grease Traps Work?

By reducing the speed of water leaving through your drain, a grease trap allows the water/grease mix to cool. This cooling will make the grease solidify, causing it to float. Heavier fragments will sink below. The remaining water is freed up to flow freely into the city sewer lines.

Formula to determine the Grease Trap size you need

Basically, the size grease trap you need, is determined by the  amount of waste streaming from your place. Sizing of grease traps determined by your GPM (Gallons per Minute). Use this easy calculator to help find your GPM production rate.

          {   ( # OF BOWLS) (LENGTH) (WIDTH) (DEPTH) (.75) (.5)    }   =  GPM                                                                          231

Examples:

THREE COMPARTMENT SINK @ 21” x 27” x 14” DEEP EACH

3 x 21 x 27 x 14 x .75 x .5 / 231 = 38.6 GPM         Recommend to use BIG DIPPER # W-500-IS

THREE COMPARTMENT SINK @ 16” x 20” x 14” DEEP EACH

3 x 16 x 20 x 14 x .75 x .5 / 231 = 21.82 GPM      Recommend to use BIG DIPPER # W-250-IS

Local CT note: Some vendors make grease traps that are not acceptable in Connecticut. Globe Equipment sells the Big Dipper brand in CT.  Many models catch the grease in a cup that can be easily emptied.  Other of types trap the grease and you’ll have to manually shovel it out of the unit.

How are Grease Traps Maintained?

In order for the Grease Trap to continue to perform efficiently, it must be maintained correctly. Improper maintenance may cause drain line blockages, back ups, foul orders and too much of the fat, oil and grease to be released into the sewer lines. Doing so, may result in large fines for your business. Please check with your local health department before setting up a cleaning plan, as many health departments have regulations and certain criteria in what actions should be taken. 

Typically, a smaller model can be manually shoveled and pumped out. Some models collect waste in a cup too be emptied as mentioned in our CT note about Big Dippers. Liquids are soak into  an absorbent, much like kitty litter. This will ensure that the waste is collected. Larger units are most often maintained by a professional recycler who will pump them out. 

Note: Keeping the materials in the grease trap cool is most important. This way when maintenance is performed on the unit, unwanted items don’t rinse or flush out the drains or Grease Trap with hot water. You want the fats, oils and grease to remain solidified. 

For more info, or to order a Big Dipper Grease Trap, call Globe at 800-972-4972.

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