High-Frequency Welded Finned Tubes ASTM A106 Gr.B Base Tube with CS Fins

Our High-Frequency Welded (HFW) Finned Tubes are engineered for reliable heat-transfer performance in industrial heating, cooling, and heat-recovery systems. The base tube is manufactured from ASTM A106 Grade B seamless carbon steel, a widely accepted standard for high-temperature service. Carbon steel fins are continuously welded onto the tube surface using high-frequency electrical energy, ensuring a consistent metallurgical bond suitable for demanding thermal environments.

• Base Tube Material: ASTM A106 Grade B (seamless carbon steel)
  • Conforms to ASME/ASTM standards for high-temperature and moderate-pressure applications.
• Fin Material: Carbon steel (typically low-carbon or mild steel)
• Manufacturing Method: High-Frequency Welding (HFW)
  • Industry-standard process for spiral-welded finned tubes.
• Typical Dimensional Range
  • Tube Outside Diameter: 19 mm – 219 mm
  • Fin Height: 8 mm – 16 mm
  • Fin Thickness: 0.8 mm – 1.5 mm
  • Fin Pitch (Fins per Inch): 2.5 – 12 FPI
• Fin Bond Characteristics:
  • Full 360° continuous weld between fin and tube
  • Uniform heat-transfer contact area
• Typical Operating Temperature Capability:
  • Up to approx. 400–450°C for standard carbon-steel finned tubes
• Surface Protection (Optional):
  • Light oil coating
  • Anti-corrosion primer
  • Other protective treatments upon request

High-frequency electrical current is directed to the contact edge between the tube and the spiral fin strip. The heat generated by electrical resistance brings the interface to welding temperature, and pressure is applied to form a solid-state weld. This process is recognized for:

• Consistent metallurgical bonding
• Reduced heat-affected zone
• High fin rigidity and adherence
• Accurate fin pitch control

• Improved Heat Transfer Efficiency
  Increased external surface area enables better heat exchange in gas-to-air and gas-to-liquid systems.

• Mechanical Durability
  Strong fin-to-tube bond reduces fin loosening under thermal cycling or vibration.

• Cost-Effectiveness
  More economical than extruded or embedded fins for moderate-temperature service.

• Customizability
  Fin dimensions, pitch, and tube sizes can be adjusted to meet design specifications.

Widely used in systems requiring enhanced heat-transfer surfaces:

• Heat Recovery Steam Generators (HRSG)
• Petrochemical heaters and coolers
• Boiler economizers
• Air preheaters (APH)
• Waste heat recovery units
• Refinery heaters and process gas coolers
• Industrial furnaces and drying equipment

Each tube can be subjected to standard quality checks such as:

• Weld bond integrity inspection
• Dimensional measurements
• Fin adherence tests
• Hydrostatic or pneumatic pressure testing (as specified by customer or code)
• Visual surface examination

These procedures ensure compliance with ASTM/ASME material standards and typical heat-exchanger fabrication requirements.