Bimetallic L-Type Fin Tubes are L-foot tension wound fin tubes where the fin material is deliberately different from the base tube material, most commonly an aluminium or copper fin wound onto a carbon steel, stainless steel, or copper alloy base tube. Pairing two different metals lets you choose the fin purely for thermal conductivity while the base tube is chosen for pressure rating and corrosion resistance, something a mono-metal L-type tube, where the fin and tube are the same material throughout, cannot do.
This bimetallic classification cuts across fin type rather than replacing it. Amardeep Steel Centre has manufactured and exported stainless steel and speciality tube products, and we are shipping to more than 40 countries.
Technical Data
Specifications of Bimetallic L-Type Fin Tubes
Parameter | Specification |
|---|---|
Fin Type | L-type, tension wound, bimetallic (fin and base tube materials differ) |
Fin Materials | Aluminium, Copper |
Base Tube Materials | Carbon Steel, Stainless Steel, Copper Alloys |
Base Tube Outer Diameter | 25 mm to 50 mm |
Fin Density | 5 to 9 fins per inch |
Fin to Tube Bond | Mechanical tension bond, approximately 75% fin-to-tube contact |
End Treatment | Tack welded or brazed at both ends |
Documentation | Mill Test Certificate supplied with every order |
Chemical Composition of Bimetallic L-Type Finned Tubes
Material | Composition Note |
|---|---|
Aluminium Fin (1100 / 1050) | 99.0% minimum aluminium |
Copper Fin (C12200) | 99.9% minimum copper |
Carbon Steel Base Tube (A179) | 0.06% to 0.18% carbon |
Stainless Steel Base Tube (TP304) | 18.00% to 20.00% chromium, 8.00% to 10.50% nickel |
Mechanical Properties of L-Type Bimetallic Fin Tubes
Material | Tensile Strength (Min) | Yield Strength (Min) | Elongation (Min) |
|---|---|---|---|
Aluminium Fin (1100) | 75 MPa | 20 MPa | 20% |
Copper Fin (C12200) | 220 MPa | 69 MPa | 35% |
Carbon Steel Base Tube (A179) | 325 MPa | 180 MPa | 35% |
Stainless Steel Base Tube (TP304) | 515 MPa | 205 MPa | 35% |
Dimension Chart of Bimetallic L-Type Finned Tubes
Base Tube OD | Fin Density | Typical Fin Material |
|---|---|---|
25 mm to 32 mm | 7 to 9 FPI | Aluminium |
32 mm to 42 mm | 6 to 8 FPI | Aluminium or Copper |
42 mm to 50 mm | 5 to 7 FPI | Copper |
Match your base tube diameter against this chart for the standard fin density and material pairing.Share your drawing with our team if your project needs a size outside these ranges.
Applications of Bimetallic L-Type Fin Tubes
- Air-Cooled Heat Exchangers: where a corrosion-resistant base tube is needed but the airside fin benefits from high conductivity.
- Refrigeration and Air Conditioning Coils: standard cooling and heating duty where cost efficiency matters.
- Process Cooling: applications where the process fluid requires a corrosion-resistant or high-strength base tube.
- Food Processing and Pharmaceutical: hygienic base tube materials paired with a conductive fin.
- Chemical and Petrochemical Air Cooling: corrosive process streams needing a resistant base tube alongside efficient air-side heat transfer.
Frequently Asked Questions
What is a bimetallic L-type fin tube?
A Bimetallic L-Type Fin Tube is an L-foot tension wound fin tube where the fin material, usually aluminium or copper, is deliberately different from the base tube material, which can be carbon steel, stainless steel, or a copper alloy.
What is the difference between a mono- and a bimetallic L-Type fin tube?
A mono L-type fin tube uses the same metal for both the fin and the base tube. A bimetallic L-type fin tube uses two different metals, letting you choose the fin purely for thermal conductivity while the base tube is chosen for pressure rating and corrosion resistance.
Does an L-type fin tube use a machined groove?
No. An L-Type fin is tension wound directly onto a smooth base tube surface with no groove involved. A machined groove is used for G Fin Tubes instead, where the fin is embedded and backfilled into the tube rather than wound onto it.
What is the maximum operating temperature for Bimetallic L-Type Fin Tubes?
Bimetallic L-type fin tubes are typically rated up to 250 degrees Celsius. The exact figure for your order depends on the base tube material and the design code your equipment is built to.
Which fin and base tube material combinations are available?
Amardeep Steel Centre supplies aluminium or copper fins on carbon steel, stainless steel, or copper alloy base tubes, with the exact pairing chosen to match your process fluid and thermal requirement.
Does Amardeep provide Mill Test Certificates with Bimetallic L-Type Fin Tubes?
Yes, every order of Bimetallic L-Type Fin Tubes ships with a Mill Test Certificate covering the chemical and mechanical properties of both the fin and base tube materials used.
Why Choose Amardeep Steel Centre
Amardeep Steel Centre has manufactured and exported stainless steel and speciality tube products since 1982, with clients across more than 40 countries. Our bimetallic L-type fin tubes are built to your fin and base tube material requirements, and every order ships with full mill documentation.
Get in touch with our team with your project specification, or send an enquiry directly for a quote on Bimetallic L-Type Fin Tubes built to your requirements.
Request a Quote