Fendium is a corrosion-protected pipe system used for fire protection in residential or industrial buildings. The steel pipes have a polymer coating on both the inside and the exterior which prevents corrosion from clogging and constricting pipes. This protection is created by a multistep chemical process which joins the polymer and steel. The resulting smooth surface reduces pipe friction which makes it possible to use smaller pumps. Further long-term advantages include weight reduction and an easier assembly.