High Frequency Welded Finned Tubes – TP321H Base Tube with Carbon Steel Fins
Product Introduction
High Frequency Welded (HF) Finned Tubes are high-efficiency heat transfer components manufactured by continuously winding and simultaneously welding a fin strip onto a base tube using high-frequency resistance welding. This process creates a strong metallurgical bond without filler material, ensuring excellent heat transfer performance, high mechanical strength, and reliability under high-temperature and high-pressure conditions.
Our TP321H Base Tube + Carbon Steel Fins HF welded finned tubes combine the superior high-temperature corrosion resistance and creep strength of TP321H stainless steel with the cost-effective thermal conductivity of carbon steel fins. They are ideal for demanding industrial environments.
Product Material
Base Tube Material: ASTM A213 / A312 TP321H (Titanium-stabilized austenitic stainless steel with high carbon content) Fin Material: Carbon Steel (typically Q235, S235JR, or equivalent) Welding Process: High Frequency Resistance Welding (HFRW)
Chemical Composition
Base Tube – TP321H
| Element |
Composition (%) |
| Carbon (C) |
0.04 – 0.10 |
| Manganese (Mn) |
2.00 max |
| Phosphorus (P) |
0.045 max |
| Sulfur (S) |
0.030 max |
| Silicon (Si) |
1.00 max |
| Chromium (Cr) |
17.0 – 20.0 |
| Nickel (Ni) |
9.0 – 12.0 |
| Titanium (Ti) |
4 × (C + N) min – 0.70 max |
| Iron (Fe) |
Balance |
Fins – Carbon Steel
| Element |
Typical Composition (%) |
| Carbon (C) |
0.12 – 0.20 |
| Manganese (Mn) |
0.30 – 0.70 |
| Phosphorus (P) |
0.045 max |
| Sulfur (S) |
0.045 max |
| Silicon (Si) |
0.30 max |
| Iron (Fe) |
Balance |
Product Structure & Manufacturing Process
The finned tube consists of three main parts:
- Base Tube (TP321H) — Provides high-temperature strength, oxidation resistance, and corrosion resistance.
- Fins (Carbon Steel) — Significantly increase the external surface area for enhanced convective heat transfer.
- Weld Seam — Formed by High Frequency Resistance Welding, creating a continuous helical metallurgical bond.
Manufacturing Process: The carbon steel fin strip is helically wound around the rotating TP321H base tube while high-frequency current concentrates heat at the contact point. Forge pressure creates a strong bond with minimal heat-affected zone, resulting in high weld integrity and excellent thermal performance.
Dimensions & Tolerances
Typical ranges (custom sizes available):
- Base Tube OD: 25 mm – 219 mm
- Fin Height: 10 mm – 25 mm
- Fin Thickness: 0.8 mm – 2.0 mm
- Fin Pitch (Density): 8 – 20 fins per inch (FPI)
- Tube Length: Up to 24 meters
Dimensional Tolerances (Reference ASME / Industry Standards):
| Parameter |
Tolerance Range |
| Base Tube OD |
± 0.75% or ± 0.5 mm |
| Wall Thickness |
± 10% or ± 0.2 mm |
| Fin Height |
± 0.75 mm |
| Fin Pitch |
± 1 fin per meter |
| Straightness |
≤ 2 mm per meter |
| Length |
± 5 mm (cut to length) |
Performance Advantages
- Excellent High-Temperature Resistance: TP321H base tube offers superior creep and stress-rupture strength up to 800°C+.
- Strong Metallurgical Bond: HF welding provides near 100% bonding efficiency with no gaps, ensuring long service life.
- High Heat Transfer Efficiency: Increased surface area (up to 8–12 times bare tube) and optimized fin geometry promote turbulent flow.
- Corrosion & Oxidation Resistance: TP321H stabilization with Titanium prevents carbide precipitation and intergranular corrosion.
- Cost Efficiency: Carbon steel fins reduce overall material cost while maintaining performance.
- Mechanical Strength: Withstands thermal cycling, vibration, and high-pressure environments.
Detailed Application Fields
These TP321H/CS HF finned tubes are widely used in:
- Power Generation: Boilers, economizers, superheaters, HRSG (Heat Recovery Steam Generators)
- Petrochemical & Refining: Fired heaters, waste heat recovery units, air coolers
- Chemical Processing: High-temperature heat exchangers
- Steel & Metallurgy: Reheating furnaces and waste heat boilers
- Cement & Incineration: Kiln exhaust gas heat recovery systems
- Marine & Offshore: Exhaust gas economizers
Our Advantages & Experience
With over 15 years of experience in manufacturing and exporting high-frequency welded finned tubes, we specialize in stainless steel base + carbon steel fin combinations for critical high-temperature applications.
Our advantages include:
- Advanced automatic HF welding production lines with strict process control.
- Full material traceability and third-party inspection (SGS, BV, TUV).
- Custom design support based on specific operating conditions (temperature, pressure, media).
- Competitive pricing combined with premium European/USA quality standards.
- Fast delivery and reliable global logistics.
We have successfully supplied thousands of tons of TP321H/CS finned tubes to power plants and petrochemical projects in Southeast Asia, Middle East, and Europe, earning consistent repeat orders from satisfied clients.
Ready to optimize your heat transfer system? Contact us today for detailed technical quotations, drawings, and samples.
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