Separator systems are needed to remove contaminants like oils and other light liquids from water. These systems are classified based on their size (NS) according to EN 858 part 2. Facilities like car washes, workshops, fuel stations, vehicle fleets, and hazardous goods stores need to have suitable separators installed.

There are two types of separators mentioned: coalescence separators (class I) and fuel separators (class II). The KLsepa.compact+ systems are coalescence separators, which have an extra unit for better separation. The KLsepa.compact systems are fuel separators. A fuel separator can remove less than 100 mg of oil per liter of water, but with a coalescence unit, it can reduce it to less than 5 mg/l.