Embedded, or G-type, fin tube starts with a groove machined into the base tube wall. The aluminium fin is wound into the groove under tension, then the displaced tube metal is rolled back over the fin foot. The fin is held by the tube material itself, not by tension alone, so the joint stays tight at metal temperatures where a wrapped fin would relax.
The trade-off is wall thickness: because a groove is cut into the tube, the base tube wall must be increased to keep the pressure rating. We calculate the required wall for the design pressure and confirm it on the drawing before production.
G-fin tubes are used in refinery and petrochemical air coolers, compressor coolers and other duties where vibration, thermal cycling or high metal temperature rule out L/LL/KL construction. Base tubes: carbon steel A179/A192/A106, stainless 304/316L, alloy steel. Fin material: aluminium, bare or coated.
Send the air cooler duty and the design pressure, and we will confirm the wall thickness and fin geometry for a G-fin proposal.
Related: Embedded (G-Type) Finned Tube · Extruded Finned Tube Production · L / LL / KL Fin Winding