Alloy Steel L-Foot Tension Wound Finned Tube for Heat Exchangers with Enhanced Heat-Transfer
Alloy Steel L-Foot Tension Wound Finned Tube for Heat Exchangers
Material Introduction
The product is a tension-wound finned tube of the “L-Foot” style, meaning that the fin strip is pre-formed into an “L” shaped foot and helically wound around a base tube under tension. This results in a strong mechanical bond between fin and tube and enhanced heat-transfer performance.
The base tube is made of alloy steel, making it suitable for higher strength, higher temperature, or more demanding environments than simple carbon steel finned tubes.
Specifications
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Base tube material: Alloy steel (can include carbon-moly, chrome-moly alloy or other alloy steel grades) as specified by the customer.
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Fin material: Typically aluminum or copper strip formed into an L-foot profile and wound under tension onto the tube.
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Tube outer diameter (typical range): ~0.5″ to ~2″ (12.7 mm to ~50.8 mm) for L-Foot tension wound fin tubes.
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Fin height: up to ~16 mm (for L-Foot type).
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Fin thickness: around 0.15 mm to 0.6 mm for typical L-type fin tubes.
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Fin pitch: 6 to 12 fins per inch (~2.4 to ~4.8 mm fin spacing).
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Length: Custom according to design requirement.
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Temperature limit: Typical up to ~130 °C (≈270 °F) for basic L-foot fin tubes.
Key Features
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The L-foot profile offers a broad contact area between fin and tube, improving heat conduction.
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Tension-wound fins ensure a firm mechanical bond, resisting loosening under vibration or thermal cycling.
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Alloy-steel core tubes provide higher strength and improved temperature capability versus plain carbon steel.
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Full fin coverage helps protect the tube surface from external corrosion.
Our Advantages
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Enhanced durability and reliability — Customers often worry about fins loosening over time. The L-foot tension-wound construction prevents this by ensuring consistent mechanical bonding.
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Improved heat-transfer efficiency — Larger fin-to-tube contact area and tighter winding improve performance, often raising efficiency significantly over standard tension-wound designs.
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Corrosion protection — Continuous fin coverage and tight adhesion reduce air-side corrosion of the base tube, increasing service life.
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Material flexibility — Both the alloy-steel tube and fin material can be customized for temperature, corrosion, or mechanical requirements.
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Cost-effective — Compared with extruded or welded fin tubes, L-Foot tension wound tubes provide excellent performance at a more economical cost level.
Chemical Composition
| Grade | C (%) | Mn (%) | Si (%) | Cr (%) | Mo (%) | Other (%) |
|---|---|---|---|---|---|---|
| ASTM A335 P9 | 0.10–0.15 | 0.30–0.60 | 0.50 max | 0.50–1.20 | 0.44–0.65 | V, Ti, Al |
| ASTM A335 P11 | ~0.08 | 0.29–0.60 | 0.50 max | 1.00–1.50 | 0.37–0.60 | V, Nb |
| ASTM A335 P22 | ~0.10 | 0.29–0.60 | 0.50 max | 2.00–2.50 | 0.85–1.03 | V, Nb |
| ASME SA179 | ≤0.30 | 0.27–0.63 | 0.10–0.35 | 0.40 max | — | — |
| ASTM A192 | ≤0.35 | 0.27–0.63 | 0.10–0.35 | 0.30–0.80 | ≤0.50 | — |
Mechanical Properties
| Grade | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) |
|---|---|---|---|
| ASTM A335 P9 | ~415 | ~205 | ≥30 |
| ASTM A335 P11 | ~415 | ~205 | ≥30 |
| ASTM A335 P22 | ~415 | ~205 | ≥30 |
| ASME SA179 | ~415 | ~205 | ≥30 |
| ASTM A192 | ~415 | ~205 | ≥30 |
Applicable Standards
Relevant execution standards for this product include:
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Base tube: ASTM A335 (P9, P11, P22), ASME SA179, ASTM A192, etc.
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Fin materials: Aluminum according to ASTM B209; Copper according to ASTM B152.
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Production specification: Tension-wound L-Foot fin profile, helical wrapping, mechanical locking.
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Testing: Hydrostatic or pneumatic tests, fin adhesion verification, dimensional inspection.
Application Fields
General uses: Heat exchangers requiring increased surface area and higher-performance alloy-steel tubes.
Specific applications include:
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Power plants: Air-cooled condensers, air preheaters, waste-heat recovery units.
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Oil & Gas / Petrochemical: Refinery coolers, process gas coolers, heat-recovery systems.
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HVAC and refrigeration: Condensers, evaporators, industrial air coolers.
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Chemical and food industry: Dryers, heaters, coolers for gas-side heat exchange.
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Marine and offshore: Air coolers exposed to corrosive marine conditions.
Q: Are you trading company or manufacturer ?
A: manufacturer,also can do trading.
Q: How long is your delivery time?
A: Generally speaking,it is 10-15 days if the goods are in stock,or it is 30-40 days if the goods are not in stock,
it is according to quantity.
Q: Do you provide samples? is it free or extra ?
A: Yes, we could offer the sample for free charge but need pay the cost of freight.
Q: What is your terms of payment ?
A: Payment<=2000USD, 100% in advance. Payment>=2000USD, 30% T/T in advance ,balance before shippment.
If you have another question, pls feel free to contact with me.
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