What is an Extruded Finned Tube
A Bimetallic Extruded Finned Tube is an advanced heat transfer component combining two distinct metals in a single structure. It leverages co-extrusion technology to fuse a high-strength inner base tube (e.g., stainless steel) with a corrosion-resistant outer fin layer (e.g., aluminum), optimizing performance in extreme thermal and corrosive environments.
The Key Features of Extruded Finned Tubes
Structure:
- Inner Tube: High-strength material (e.g., carbon steel, stainless steel) for structural integrity and pressure resistance.
- Outer Fins: Corrosion/abrasion-resistant metal (e.g., aluminum, copper) extruded seamlessly from the tube.
Extruded Fin Tube Manufacturing Process:
- Fins are cold-extruded from the outer metal layer, creating a monolithic bond with the inner tube.
- Eliminates thermal contact resistance between layers.
The Manufacturing Process of Extruded Finned Tubes
Material Preparation
- Base Tube Selection:
Materials such as carbon steel, stainless steel (304/316), or copper are chosen for their thermal conductivity and corrosion resistance. - Aluminum Tube Matching:
Aluminum tubes (e.g., Al 6061/6063) are sleeved over the base tube, with wall thickness tolerance controlled within ±0.1 mm.
- Base Tube Selection:
Pre-Treatment
- Base and aluminum tubes undergo degreasing and acid pickling to remove oxides and contaminants, ensuring clean bonding surfaces.
Sleeving Aluminum Tube
- Aluminum and base tubes are assembled with a clearance fit (0.1–0.3 mm) and tightly sleeved using hydraulic or mechanical methods.
Extrusion Forming
- Cold/Hot Extrusion:
- Cold Extrusion: Performed at room temperature under 200–400 MPa pressure, suitable for plastic deformation of aluminum tubes.
- Hot Extrusion: Aluminum is heated to its recrystallization temperature (~350–450°C) to reduce deformation resistance.
- Mold Design:
Helical or longitudinal fin molds are used, with multi-stage forming rollers ensuring fin height precision (±0.2 mm).
- Cold/Hot Extrusion:
The Advantages of Extruded Finned Tubes
Monolithic Construction
- Seamless integration of fins and base tube eliminates weld points, reducing leakage risks and enhancing pressure resistance (up to 30 MPa).
High Thermal Efficiency
- Tight fin-to-tube bond and customizable fin density maximize heat transfer surface area.
Corrosion Resistance
- Uniform material composition (e.g., stainless steel, Inconel) prevents galvanic corrosion, ideal for acidic/alkaline environments.
Extreme Temperature Tolerance
- Withstand temperatures from -200°C to 600°C without thermal stress cracking due to homogeneous thermal expansion.
Low Maintenance Design
- Smooth, continuous fins resist fouling and abrasion in high-particulate gas/liquid flows.
Material Versatility
- Compatible with aluminum, copper, titanium, and high-performance alloys for specialized applications.
Cost-Effective Longevity
- 20–30% longer service life than welded fins in aggressive industrial settings, reducing replacement frequency.
The Disadvantages of Extruded Finned Tubes
Material Restrictions
- Limited to ductile metals (aluminum, copper); unsuitable for brittle alloys like titanium.
- Base tube wall thickness reduced by 15–30%, weakening high-pressure resistance.
Complex Manufacturing
- Requires costly precision molds, increasing tooling expenses by 40–60%.
- Energy-intensive process (20–30% higher than welding).
Fin Design Limits
- Max fin height: 20 mm (aluminum) or 15 mm (copper); higher fins risk cracking.
- High-density fins (>8/cm) weaken root strength due to stress concentration.
Efficiency Loss
- Micro-gaps at fin-base interface raise thermal resistance by 10–15%.
- Tight fin spacing (<3 mm) traps dust, cutting efficiency by 25% over time.
Maintenance Challenges
- Damaged fins require full tube replacement; no in-situ repair.
- Coatings peel at fin roots, accelerating corrosion.
Cost & Sustainability Issues
- 5–8% scrap rate during production.
- Mixed-material designs hinder recycling (e.g., aluminum/steel).
Sizes and Materials of Our Extruded Finned Tubes
| Base Tube Diameter | 19 to 60.3 mm | 3/8″ to 2″ NPS |
| Base Tube Wall Thickness | 0.5 to 4 mm | 0.02″ to 0.16″ |
| Base Tube Length | ≤32,000 mm | ≤92 ft |
| Base Tube Material | Carbon Steel (A106B, P235GH, A179, A210, A192, etc.) Alloy Steel (P5, T5, P9, T9, T11, T22, etc.) Stainless Steel (TP304, TP316, TP347, B407 800H/HT, etc.) aluminum, copper | |
| Fin Pitch | 78 to 472 FPM | 2 to 12 FPI |
| Fin Height | 5 to 16 mm | 0.19″ to 0.63″ |
| Fin Thickness | 0.3 to 1.2 mm | 0.01″ to 0.05″ |
| Fin Material | aluminum, copper | |
| Fin Type | Extruded | |
For other customized requirements, please contact us.
Our Production Capacity of Extruded Finned Tubes
Total twelve extruded fin tube machines, monthly production capacity is 150,000 meters in total.
Extruded Finned Tubes Uses
- Oil & Gas: Heat exchangers in sour gas processing or offshore platforms.
- Waste Heat Recovery: Combustion exhaust systems with acidic condensate.
- Marine Engineering: Seawater-cooled condensers and desalination plants.
Comparison with Other Finned Tubes
| Type | Structure | Best For |
|---|---|---|
| Bimetallic Extruded | Dual-metal, seamless bond | Corrosive + high-pressure |
| Single-Metal Extruded | Single-material fins/tube | Non-corrosive, high-temperature |
| G-Type Embedded | Mechanically embedded fins | Abrasive, high-vibration |
| Welded Serrated | Welded serrated fins | Dust-heavy environments |
Why Choose Us
- a 16-year aluminium extruded fin tube manufacturer. We are experts.
- solutions for all your needs
- the highest product quality
- the low lead times
- excellent customer service
