"G" Embedded Fin Tube
Fin strip rolled into a machined groove in the tube wall for permanent metal-to-metal contact
What "G" Embedded Fin Tube Is
An embedded fin tube carries its fin inside a helical groove machined into the base tube wall, and the displaced parent metal is rolled back to lock it there.
That mechanical anchor is why G type tubes keep their heat transfer rate at service temperatures where a simple tension-wound fin would loosen and lift off the tube.
Fanbang produces G type tubes on six dedicated G and L type production lines for air-cooled heat exchanger builders, gas processing contractors and power plant OEMs.
Why Engineers Specify It
Fin stays tight when the tube runs hot
The groove plus the rolled-back shoulder holds the fin under compression, so the bond does not rely on residual tension alone.
Wide base tube range in one process
16 mm to 80 mm outside diameter covers both small bore cooler bundles and heavy process tubes without changing supplier.
Dissimilar metals without welding
An aluminium or copper fin can be embedded onto a stainless, titanium or nickel base tube, so the corrosion side and the heat transfer side are chosen separately.
Predictable bundle geometry
Fin pitch is held between 2.0 mm and 5.0 mm across the tube length so bundle pressure drop matches the thermal design.
Where It Is Used
- Heat exchanger units for electric, nuclear, thermal and geothermal power plants
- High corrosion service such as condensers, evaporators, sea water desalination, fertiliser and urea systems, ammonia, gas and corrosive acids
- Petroleum, chemical and petrochemical processing
- Food processing and refrigeration
- Natural gas treatment
Buyers Who Come to Us for This Tube
Air cooled heat exchanger builders
Bundles that run above the safe service range of a plain wound fin.
Gas processing and treatment contractors
Coolers handling gas streams where fin loosening means a bundle replacement, not a repair.
Power plant maintenance teams
Replacement tubes matched to an existing bundle pitch and fin height.
What Goes Wrong Without It
Fins lifting off after thermal cycling
The embedded groove keeps contact area intact through repeated heat-up and cool-down cycles.
Losing heat transfer over a bundle's life
A mechanical lock preserves the metal-to-metal path that drives the overall transfer coefficient.
Corrosive process fluid inside, cheap fin outside
The base tube alloy is selected for the process; the fin is selected for cost and conductivity.
"G" Embedded Fin Tube Dimensions
These are the ranges our production lines run. Sizes outside them are quoted case by case rather than assumed.
| Item | Specification |
|---|---|
| Base tube diameter | 16 mm - 80 mm |
| Base tube wall thickness | 1.65 mm - 4.0 mm |
| Fin thickness | 0.3 mm - 1.2 mm |
| Fin pitch | 2.0 mm - 5.0 mm |
| Fin height | 10 mm - 16 mm |
Materials
| Component | Materials available |
|---|---|
| Base tube | Stainless steel, carbon steel, alloy steel, titanium, nickel, copper |
| Fin strip | Aluminium strip, copper strip |
How It Is Made
"G" Embedded Fin Tube on the Shop Floor
Inspection and Certification
Every tube passes eddy current and hydrostatic testing, with tensile, flattening, flaring, hardness and chemical analysis carried out on our own equipment. Fin pitch, fin height and finned length are verified as dimensional items in their own right.
The company holds ISO 9001:2015, CE certificate, Production licence for pressure pipe.
What Can Be Changed
- Base tube material and wall thickness within the range above
- Fin material, fin pitch and fin height to the bundle design
- Finned length and bare end length for the tubesheet joint
- Marking, packing and certificate scope for the destination market
Compared With the Alternatives
Compared with an L type tension-wound fin, the G type holds up at higher metal temperatures because the fin is anchored rather than held by tension. Compared with an extruded fin tube, it accepts a much larger base tube diameter and leaves the base tube bore untouched, but it does not give the single-piece bimetal wall that extruded tubes provide.
Use Guide
- Give the bundle design temperature, not just the process temperature, so the fin material and groove depth can be matched to the hottest metal condition.
- State base tube material and wall thickness together; groove depth is taken from wall thickness, so a thin wall limits the fin foot.
- Send existing bundle drawings when ordering replacement tubes so fin pitch and finned length match the tubesheet layout.
"G" Embedded Fin Tube FAQ
What is the maximum base tube diameter you can embed?
Up to 80 mm outside diameter, with a wall thickness from 1.65 mm to 4.0 mm.
Can the fin be aluminium on a stainless steel tube?
Yes. The base tube and the fin strip are specified separately - aluminium or copper fin strip on a stainless, carbon, alloy, titanium, nickel or copper base tube.
What fin pitch range is available?
2.0 mm to 5.0 mm, with fin height from 10 mm to 16 mm.
Do you supply tubes for existing bundles?
Yes. Send the bundle drawing or a sample tube and we match base tube size, fin geometry and finned length.
Often Compared With
L/LL/KL Fin Tube
Tension-wound foot fin in three footprint styles, the standard choice for air cooled heat exchangers
Base tube diameter: 19 mm - 51 mm · Base tube wall thickness: 1.65 mm - 3.0 mm
Extruded Fin Tube
Bimetal tube with the fin extruded from an outer sleeve, giving a seamless fin-to-tube wall
Base tube diameter: 10 mm - 51 mm · Base tube wall thickness: 1.65 mm - 3.0 mm
Low Fin Tube
Integral low fin rolled from the tube wall itself, for shell and tube exchangers
Base tube diameter: 12.7 mm - 31.8 mm · Base tube wall thickness: 1.65 mm - 3.0 mmIndustries using this tube
Related reading
Quote "G" Embedded Fin Tube From Your Drawing
Send base tube size, wall thickness, fin geometry, material and length. You get a quotation against the drawing, not a catalogue page.
[email protected] · Tel 0086 512 58392615 · Monday to Saturday, 08:30 - 17:30 China Standard Time (GMT+8)