The oily water go through a first compartment, then travels along the principal capacity where the separation of water, oil and sediments, occur by gravity. The hydrocarbons accumulated on the surface are then recovered continuously without water by an oleophilic drum.

The separator can be used alone or associated to an induced air or gas flotation.
Three models of separator are proposed :
- A range of 10 parallelepipedic separators, model DP, which can treat flows of 1 to 500 m3/h.
- The DPC separators are cylindrical and can operate under pressure.
– The DPS separators are equipped with filters in the last compartment, as presented below.