Operation and maintenance of a grease trap

The grease trap is an essential element for the proper functioning of a restaurant. 

It’s important to maintain properly the grease trap in a commercial restaurant. We will explain how it works and how to properly maintain it and avoir potential damage.

The operation of a grease trap

The ability to retain grease is achieved by a level of grease accumulation on the surface of the water inside the basin. The level of grease and light waste must never exceed 25% of the liquids contained in the grease trap.

Sketch of the operation of a traditional grease trap:

1: Dirty water inlet
2: Lamellars that separate water and grease
3: Accumulator
4: Exit of treated water

A: Available space
B: Accumulated grease
C: Light waste
D: Treated water
E: Heavy waste

As soon as the level of # C is lower than that of the accumulator # 3, the grease trap no longer carries out its function and there is a risk of overflows and drainage problems in the facility.

Operation of a grease trap

Maintenance of a grease trap

It is essential to remove the cover when emptying the grease trap, because liquids and waste (light and heavy) must be removed completely during each cleaning. Thorough rinsing must also be done with each cleaning to remove any residue that remains stuck to the wall.

The level of grease and oil floating above the trap basin must never exceed 2″ in depth.

Here’s how to assess the level of grease in your trap:

  1. Open the cover of the trap and use a baster to break the layer of grease on top. If the layer is thick and solidified, you should immediately clean it up. If the layer breaks easily and is liquid, proceed to step #2.
  2. Take a sample of liquid with the baster at about 1″. If the sample contains grease, perform the same procedure, but at a depth of 2”. If it still contains grease, perform the same procedure a 3rd time at a depth of about 2-½”. If you do not collect water, but more grease instead, it means that the grease trap must be cleaned.

Determine your cleaning frequency

It is important to know how often you need to empty your grease trap. It’s different for each facility.

For the first time, (or after cleaning), every week, you can assess the level of grease in your trap. After a few weeks or months, when you have reached 2″ of residue, you will then know the approximate frequency at which you should have your grease trap cleaned. Note that regardless of the level of grease, it must be cleaned at least every 3 months to prevent the residues from solidifying and damaging the grease trap.

Example of a good grease trap cleaning

We have been specializing in restaurant construction for over 26 years. Do you have other questions for the maintenance of your restaurant equipement ? You can contact us and we can help you !

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