SpiralEdge™ Outer Fin Tubes
Integral external helical fins for increased surface area and efficient heat transfer
SpiralEdge™ outer fin tubes are formed by a rolling process that raises fins in a continuous spiral on a straight length of tubing — creating a greatly increased surface area of known dimensions with fins that are completely integral to the tube wall.
During the finning operation, the inside diameter of the base tube is reduced and helical fins are rolled out of the tube wall. As a result, the fin outside diameter becomes smaller — or at least not larger — than the permissible outside diameter of the unfinned tube sections.
A key advantage of this finning procedure is that it can be interrupted at any point of the tube. The unfinned tube sections (intermediate landings) make it possible to support and fit finned tubes in shell-and-tube heat exchangers in the same way as plain tubes. SpiralEdge™ outer fin tubes are normally produced with both ends plain; intermediate landings can be provided as required.
Key Features
- • Integral helical fins formed by rolling — fins are completely integral to the tube wall
- • Greatly increased external surface area with known, repeatable dimensions
- • Finning can be interrupted to create intermediate landings for easy exchanger assembly
- • Tubes typically supplied with plain ends; intermediate landings available on request
- • Produced from precision smooth tubes with strong dimensional control
- • Fin density available across a wide range (typical: 16–48 FPI; other densities on request)
- • Can be supplied in “as finned” condition; annealed temper available on request (material dependent)
- • Supplied with deburred / smooth ends
Product Families Covered on this Page
* For internally finned / internally grooved (plain OD) tubes, see the SpiralEdge™ Inner Groove page.
Typical Ranges (Outer Fin Products)
| Product Type | OD Range | Wall Thickness | Fin Density | Length | Notes |
|---|---|---|---|---|---|
| Integral Fin Tubes | 9.52 to 42.00 mm | 0.90 mm+ | 11 to 48 FPI (typ.) | Up to 10 m | Plain ends; intermediate landings on request |
| Turbo Chill Tubes | 15.87 & 19.05 mm | Varies by size | 19 / 22 / 26 / 40 | Up to 8 m | OD fins + internal ridges (8/10 typical; others on request) |
| Condenser Tubes | 15.87 & 19.05 mm | Varies by size | 40 / 42 / 48 | Up to 8 m | OD fins + internal enhancements for refrigerant condensers |
| Corrugated Fin Tubes | 7.90 to 38.10 mm | 0.50 to 2.11 mm | Pitch: 3 to 12 mm | Up to 10 m | Internal + external spiral corrugations (thin-wall capability) |
| End Cross (Knurled) Fin Tubes | 12.70 / 15.87 / 19.05 mm | As low as 0.55 mm | 26 FPI | Up to 8 m | Smooth bore or internal ridges; commonly used in VAM chillers |
* For calculation of surface area of fin tubes (integral / turbo chill / condenser / corrugated), please contact us.
* Sizes/fin densities not listed can be produced on request; medium/high fin parameters available on request.
* Tubes can be supplied in “as finned” condition; annealed temper available on request for select materials.