They consist of paddles screw-mounted to the shaft, which is connected to the gear drive by a fl ange and mating fl ange assembly. The scrapers adapt to any shape and diameter of fl at or pitched tank fl oor. Their low rpm allows tines to be added to the centre to separate sludge from the water more easily, causing high-density matter to fall to the bottom and the water to rise. The tines signifi cantly increase the performance of the scraper.