High Frequency Finned Tubes

Delfin Tubes, S.A. supplies the highest quality welded finned tubes to any part of the world. The newly designed manufacturing facility, with our state-of-the-art high frequency resistance welding machines, enable us to perform large scale projects in reduced times.

The steel fin, that may be solid or serrated, is helically wound and continuously welded to the tube by high frequency electric resistance welding. This produces an homogeneous, clean and continuous fin-totube bond with no additional weld material, for a very efficient heat flow and resistance to corrosion.

There are some applications for which one or the other fin type is preferred. While in some cases fouling and cleaning considerations will favour solid fins, serrated fins are superior with respect to weight, compactness and price.

The use of high-frequency current results in very localised heating of the tube surface and the edge of the fin. This skin effect produces higher weld speeds, hence post-weld heat treatment is not considered necessary because of the superficial nature of the changes in the microstructure.

Tube bending:

Our finning machines are equipped with online single or duplex cold bending equipment that can manipulate both ends of tubes in a single operation, thus ensuring exact alignment of the ends. Our bending machines are capable of bending both bare or finned tubes with diameters from 31 mm to 76 mm.

Corrosion protection:

If required, the external surfaces of finned tubes can be treated with a protective coating. Our engineers are always ready to assist you with design considerations to meet your specific product needs.

Uses of  finned tubes

The main uses for high frequency welded finned tubes are in the heat recovery associated with boilers for power generation and in furnace applications for the petrochemical industry.

Sizes and materials

Our high frequency welding finning machines are capable of handling tube diameters from 21 mm o/d to 273 mm o/d and tube lengths of up to 26 meters. Fin sizes range from 6 mm to 38 mm high and from 0.8 mm to 3 mm thick.

Dimensional Data Sheet

Any combination of the following materials may be used for fin and tube: carbon, alloy, stainless steels and high nickel alloys.