Gravity Grease Separation

How gravity grease traps work

Fat, oil and grease have lower specific gravity than water and as a consequence, it floats to the surface. This principle makes a conventional grease trap extremely simple and very effective.

Typically, a grease trap comprises a chamber divided by an integral baffle wall. The wall runs from the top of the chamber to just short of its base so when the chamber is filled with water, anything that floats on the surface will be trapped by the baffle and contained within the first section of the vessel.

The grease trap system separates fat, oil and grease as follows:

Kitchen effluent passes into the chamber which slows the flow and allows the oil content to separate and float to the surface. The separated oil is contained using the baffle wall and forms a layer on the surface. ‘Cleaned’ water is allowed to pass under the baffle wall and into the main drainage system.

This separation principle is employed in grease traps ranging from indoor, under counter units to large below ground systems and automatic grease separators.

Filta supply grease traps for all applications from 20-litre stainless steel under sink units to 8000 litre underground separators.

Once installed, the grease trap will require regular emptying using a vacuum unit to maintain its effectiveness or regular treatment using a biological additive (see grease treatment).

Our service is carried out in 3 Stages:

Site Survey

Site Survey

Filta will survey your establishment, to correctly identify your requirements.



Our trained engineers will install a grease management system to suit your needs.



On a regular basis, we will ensure the equipment is working effectively & efficiently.

For more information about our grease management products and services or to discuss the requirements of your commercial kitchen, contact our team on 01788 550100.