What are High Frequency Welded Serrated Finned Tubes
A High Frequency Welded (HFW) Serrated Fin Tube is a specialized heat exchange component consisting of a base tube with externally attached serrated fins that are bonded to the tube surface through high-frequency induction welding. Unlike solid fins, serrated fins feature notched edges that increase turbulence and surface area, enhancing heat exchange performance.
The Key Features of High Frequency Welded Serrated Finned Tubes
Structure:
- Base Tube:Usually carbon steel pipes, stainless steel pipes, or corrosion-resistant alloy steel pipes.
- Fins: Serrated (notched) metal strips welded to the tube surface, creating turbulence in the fluid flow.
- Bonding Method: High-frequency welding creates a metallurgically fused, leak-proof joint.
How It Works:
- Serrated edges disrupt airflow/fluid flow, breaking the thermal boundary layer.
- This turbulence improves heat transfer rates by up to 20-30% compared to solid fins.
The Manufacturing Process of High Frequency Welded Serrated Finned Tubes
Material Preparation
- Base Tube Material: Typically carbon steel pipes, stainless steel pipes, or alloy steel pipes, selected based on corrosion resistance, temperature tolerance, and mechanical strength requirements.
- Fin Strip Material: Aluminum fins, copper fins, or steel strips are common. Serrated fins are precision-cut or cold-formed to create a zigzag edge, optimizing surface area and thermal performance.
- Surface Treatment: Base tubes and fin strips undergo degreasing, pickling, or sandblasting to remove oxides and contaminants, ensuring optimal weld quality.
Fin Formation and Alignment
- Serrated Fin Fabrication:
- Cold Forming: Fin strips pass through rolling mills or presses to create uniform serrations (teeth-like notches) along their edges.
- Laser Cutting: Advanced methods use laser systems to cut precise serrations, ensuring consistency and minimizing material waste.
- Fin Positioning: Serrated fins are helically wound or longitudinally aligned around the base tube using automated machinery. Precise spacing between fins is maintained to balance heat transfer and airflow resistance.
- Serrated Fin Fabrication:
High-Frequency Welding
- Current Application: A high-frequency alternating current (100–400 kHz) is induced into the fin and tube interface, creating eddy currents that rapidly heat the metals to 1200–1400°C.
- Pressure Welding: Mechanical pressure is applied to fuse the heated fin base with the tube surface, forming a continuous, void-free weld seam.
- Cooling: Air or water quenching solidifies the weld zone, ensuring structural integrity and resistance to thermal fatigue.
Quality Control of Serrated Finned Tubes
- Pull-off tests verify welding strength (>200 MPa)
- Microscopic examination checks heat-affected zone depth (<0.5 mm)
- Dimensional inspections ensure fin spacing tolerance (±0.2 mm)
The Advantages of High Frequency Welded Serrated Finned Tubes
Enhanced Heat Transfer Efficiency
- Serrated edges disrupt fluid boundary layers, creating turbulence that boosts heat exchange rates by 20–30% compared to smooth fins.
Superior Structural Integrity
- High-frequency welding ensures full metallurgical bonding between fins and base tube, achieving weld strength ≥90% of the parent material.
Corrosion and Oxidation Resistance
- Serrated finned tubes are compatible with protective coatings (e.g., galvanizing, anodizing) and stainless-steel alloys, optimized for harsh environments (e.g., acidic/alkaline conditions).
Reduced Fouling and Maintenance
- Turbulent airflow across serrations minimizes particulate buildup, extending service intervals.
Lightweight and Compact Design
- Aluminum fins reduce weight by 40–50% versus solid steel tubes, ideal for space-constrained installations.
High-Temperature Durability
- Serrated finned tubes withstand operating temperatures from -50°C to 600°C, suitable for boilers, economizers, and exhaust systems.
Cost-Effective Production
- Automated HF welding enables rapid manufacturing (up to 30 m/min) with minimal material waste.
Versatile Applications
- Serrated finned tubes are widely adopted in power plants, refineries, HVAC, and renewable energy systems for optimized thermal management.
The Disadvantages of High Frequency Welded Serrated Finned Tubes
High Initial Costs
- Advanced equipment (e.g., HF welding machines, laser cutters) and skilled labor increase production expenses.
Complex Fabrication
- Precision alignment of serrated fins and strict parameter control (e.g., temperature, pressure) demand rigorous quality oversight.
Material Limitations
- Thin or low-melting-point alloys (e.g., aluminum) risk deformation during welding; stainless steel requires costly inert gas shielding.
Stress Concentration
- Serrated edges create localized stress points, increasing susceptibility to fatigue cracks under vibration or thermal cycling.
Reduced Pressure Tolerance
- Serrated finned tubes are weaker mechanical strength compared to solid finned tubes, limiting use in ultra-high-pressure systems (>10 MPa).
Fouling Susceptibility
- Particulate accumulation in serrations may offset turbulence benefits, requiring frequent cleaning in dusty environments.
Energy-Intensive Process
- HF welding consumes significant electricity (~5–10 kWh/meter), raising operational costs for large-scale production.
Limited Repairability
- Damaged fins or weld seams often require full tube replacement due to challenges in localized repairs.
Dimensions and Materials of Our High Frequency Welded Serrated Finned Tubes
| Base Tube Diameter | 16 to 350 mm | 3/8″ to 14″ NPS |
| Base Tube Wall Thickness | 2 to 30 mm | 0.08″ to 1.18″ |
| 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.) | |
| Fin Pitch | 39 to 277 FPM | 1 to 7 FPI |
| Fin Height | 8 to 35 mm | 0.31″ to 1.38″ |
| Fin Thickness | 0.5 to 3 mm | 0.02″ to 0.12″ |
| Fin Material | Carbon Steel, 2.25Cr-1Mo, 5Cr-0.5Mo, 11-13Cr (409, 410), 18Cr-8Ni (SS 304), 25Cr-20Ni | |
| Fin Type | “U” or “V” Serrated | |
For other customized requirements for serrated finned tubes, please contact us.
What is the Price of High Frequency Welded Serrated Finned Tubes
Please contact our sales manager Allen@sanesteel.com.
Our Production Capacity of High Frequency Welded Serrated Finned Tubes
Total four high frequency welded serrated finned tubes machines, monthly production capacity is 1200 tons in total.
High Frequency Welded Serrated Finned Tubes Uses
- Serrated Fin Tube Heat Exchangers
- Serrated Fin Tube Radiators
- Serrated Fin Tube Coolers
- Serrated Fin Tube Evaporators
- Serrated Fin Tube Heaters
- Serrated Fin Tube Radiation Heaters
- Serrated Fin Tube Boilers
- Serrated Fin Tube Convectors
- Serrated Fin Tube Economizers
- Serrated Fin Tube Condensers
- Serrated Fin Tube HVAC Systems
Comparison with Other Finned Tubes
| Type | Fin Design | Heat Transfer | Typical Use |
|---|---|---|---|
| HFW Serrated Finned Tubes | Notched, welded | ⭐⭐⭐⭐⭐ | High-efficiency gas systems |
| HFW Solid Finned Tubes | Smooth, welded | ⭐⭐⭐⭐ | High-pressure steam systems |
| Extruded Finned Tubes | Hollow, wrapped | ⭐⭐⭐ | Moderate-temperature fluids |
| Embedded Finned Tubes | L-shaped, grooved | ⭐⭐ | Low-corrosion environments |
Maintenance Guidelines of High Frequency Welded Serrated Finned Tubes
Routine Inspections of Serrated Finned Tubes
- Visual checks for fin damage
- Monitoring pressure drop trends
- Thermal imaging for hot spots
Cleaning Methods
- Air or water blasting (gentler than for smooth fins)
- Chemical cleaning (compatible with materials)
- Avoid mechanical brushing that could damage serrations
Repair Options
- Spot welding for minor fin damage
- Section replacement for severe cases
- Professional assessment for critical applications
Why Choose Us
- a 16-year serrated finned tubes manufacturer. We are experts.
- solutions for all your needs
- the highest product quality
- the low lead times
- excellent customer service
