Integral Finned Tubes

Integral fin tubes were developed to increase the heat transfer performance of fluids while reducing the physical size and cost of the heat exchanger. In these tubes the fins are rolled out from the wall of the tubes and hence are integral with the tube. As the fins are formed from the base tube by rolling out material from its wall, the wall thickness under the finned section is reduced compared to the wall thickness at plain ends. These fin tubes can be manufactured from most tubular materials and the hardness of the material usually determines the finning code or fin profile. The harder materials such as Nickel Alloys, Stainless Steel, Titanium are supplied with higher density (i.e 26,28,30 or 36 FPI). This shallow profile reduces the work hardening of the material and helps eliminate the possibility of root fin cracking.

Whereas, with softer materials like Carbon Steel, Copper, and Copper Alloys are supplied with deeper profile giving a lower fin density (i.e 16 or 19 FPI).
These tubes can also be supplied with intermediate plain landing as well as U Bent, where the U Bend portion can be Finned or Un-Finned.