... soft, medium, mid-firm, and firm. For new equipment, soft and mid-soft balls are the best choice. For equipments in routine ... used for cleaning the softness and hardness settlings of the copper pipe,steel pipe,Titanium tube,etc.Technical data Sponge Ball ... burns with sootStabilityNot available with acids, alkalis, oils, fats and solvents. high quality rubber sponge cleaning ball for pipeline cleaning