WELD Hydrocarbon separators – class 2 – are intended for separation and retention of mud and hydrocarbons contained in rainwater or waste waters. It works through the difference in density between water and hydrocarbons. Liquid hydrocarbons are lighter than water and climbs to the surface being captured in a retention room. Hydrocarbon separators are equipped with a mud decanter, a filter mounted on the output, but also with a bypass in case of need.