It is based on the density difference between the particles inside the grease interceptor.

Greases, with a density of 0.95, rise to the surface while heavy matter with a density of 1.1 settle to the bottom of the interceptor.

The grease-containing water arrives in the interceptor through the inlet device (1), fitted with an anti-splash nozzle to avoid stirring up the sludge and grease that have already decanted out (2).

The partition (3) retains the sludge in the first part and the outlet siphon (4) keeps the grease inside the interceptor.