Manufacturing Process

From incoming tube inspection to export packing — the eight production steps behind every finned tube we ship.

1. Incoming material inspection

Every base tube and fin strip is checked against its mill certificate: grade, heat number, dimensions and surface condition. Tubes with laps, seams or excessive ovality are rejected before they reach a machine.

2. Tube preparation

Tubes are cut to length, ends are squared and, where required, the surface is cleaned. For welded products the weld area is degreased to avoid porosity.

3. Fin forming

Product	Equipment
Extruded fin	Three-roller extrusion head, one pass per tube
Embedded G fin	Grooving head plus rolling head
L / LL / KL fin	Winding machine with tension control
HF welded fin	High-frequency welder with strip feed
Laser welded fin	Fibre laser welding head on a rotating axis
Integral fin	Rolling head with internal mandrel

4. In-process inspection

Fin height, pitch and thickness are measured every batch; the finned length and bare end lengths are checked against the drawing. For welded products the weld bead is inspected visually and, where specified, by penetrant or ultrasonic methods.

5. Heat treatment and surface treatment

Stress relief is applied for alloy steel products where the specification requires it. Optional surface treatments include hot-dip galvanising, epoxy or phenolic coating, and pickling and passivation for stainless steel.

6. Pressure and leak testing

Hydrostatic testing to 1.5 times design pressure, or pneumatic testing where water is not permitted. Test pressure, hold time and results are recorded per bundle.

7. Dimensional and documentation review

Final dimensional check, visual inspection and a documentation pack: mill certificates, inspection reports, test records and packing list.

8. Packing

Tubes are bundled, end-capped, wrapped in VCI film and packed in sea-worthy wooden cases. Long tubes are supported to prevent sagging during ocean transport.