How Are Finned Tubes Made?

Union Steel Industry is a leading manufacturer of Finned Tube Products. We offer our customers several styles of finned tubes and use three different processes to create our fins.

- The first is to apply the tape to the outside of the tube perpendicular to the tube configuration.

- The second is to form or press the fins into the tube wall to form extruded fins.

- The third is to form the tube using a die to create dimples or shapes in the tube wall.

Manufacturing Process of Finned Tube:

Fin strips are continuously welded and helically wound on polished bare tubes. The tubes and fins are joined together using high frequency resistance welding techniques. We manufacture solid flat and serrated spiral welded steel finned tubes. Also, all spiral welded tubes can be bent in the middle or at the end of the finned tubes, which we call hairpin tubes.

Acceptance Criteria:

International Standard or Customer's Delivery Conditions (TDC) for Dimensions, Tolerances and Testing of High Frequency Resistance Welded Fins.

Visual Inspection:

Unwelded parts of fins, fin damage after refining, copper contamination, tearing, wrapping, etc.

Dimensional Inspection:

Fin height, fin pitch, fin inclination, fin corrugation, length of finned and non-finned parts, etc.

Bending Check:

Ovality, thickness and area are reduced.

Surface Coating:

The exterior is a red zinc oxide phosphate primer and the interior is a Volatile Corrosion Inhibitor (VCI) in the form of a water soluble tablet.

Tube End Treatment:

Angle@(30°~35°)

Diagonal Root Size:

0.5mm~1.5mm