Flaking installations are installations in which we add an inorganic salt, such as polyaluminium chloride, or an iron sulphate ion, together with a polyelectrolyte to separate out contamination. A flaking installation is similar to a physical-chemical installation in terms of construction and installation. In both cases, chemicals are first injected, separation then occurs, following which sludge is drained. Flaking installations can be used on almost any type of waste water. A flaking installation is often part of an installation that consists of several techniques. The specification of a flaking installation depends upon the composition of the waste water. The capacity runs from 1 m3 per hour to 400 m3 per hour.