Cleaning U-tubes can be daunting, but Goodway U-tube Tool Brushes make it easy. These brushes are designed to snake partially through each side of a U-bend, to thoroughly remove scale and other deposits from tubes 1/2"-3/4" (12.7-19.1mm) I.D.
The Flexible Arm Flare Cone Tool is designed for tubes 4"-12" (102-305mm) I.D. It incorporates centrifugally activated serrated cones for removing light to heavy scale deposits in straight or curved tubes. Most effective results are obtained if the tube is in a vertical position when cleaning.