ASTM A213 T22 Helical Serrated Fin Tube with SS409 Fins For Refinery Heat Exchanger

ASTM A213 T22 Helical Serrated Fin Tube with SS409 fins is a high-efficiency heat transfer component widely used in high-temperature industrial thermal equipment. The base tube is manufactured in accordance with ASTM A213 standard, made of T22 (2.25Cr-1Mo) alloy steel, which features excellent high-temperature strength, creep resistance and thermal stability. Helical serrated fins made of SS409 ferritic stainless steel are tightly bonded onto the outer surface of the base tube, normally by high-frequency welding.

The serrated fin design effectively breaks the gas boundary layer, strengthens turbulence and significantly improves overall heat exchange efficiency compared with conventional solid helical fins. SS409 provides good oxidation resistance and moderate corrosion resistance at an economical cost. This fin tube combines reliable high-temperature performance of T22 base tube and enhanced heat transfer performance of serrated SS409 fins, making it ideal for boilers, waste heat recovery units, refinery heaters and petrochemical heat exchangers.

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Here are some detailed breakdowns:

1. Base Tube

Chemical Composition of ASTM A213 T22 (UNS K21590)

Mechanical Properties of ASTM A213 T22

2. Key Properties of SS409 (UNS S40900) Ferritic Stainless Steel

Material type: Ferritic stainless steel, 11–13% Cr, stabilized with titanium

• High-temperature oxidation resistance: Excellent service performance up to 650°C
• Corrosion resistance: Good resistance to atmospheric corrosion, flue gas corrosion, and moderate oxidizing media
• Thermal expansion: Coefficient close to carbon steel and T22 alloy tube → less thermal stress
• Mechanical strength: Good rigidity and formability for fin rolling and welding
• Cost advantage: Much more economical than 304, 316, 430 stainless steel
• Magnetic: Typical ferritic structure, stable under high temperature

3. Advantages of ASTM A213 T22 Helical Serrated Fin Tube with SS409 Fins

• Superior high-temperature strength & creep resistanceThe base tube made to ASTM A213 T22 (2.25Cr1Mo) provides excellent stability under high-temperature and high-pressure conditions, widely recognized for use in boilers, heat exchangers, and process heaters.
• Enhanced heat transfer efficiencyHelical serrated / notched fins disrupt the thermal boundary layer, reduce laminar flow, and significantly improve overall heat exchange performance compared with smooth or plain helical fins.
• Cost-effective corrosion & oxidation resistanceSS409 ferritic stainless steel fins offer good heat resistance, moderate corrosion resistance, and better economy compared with 304/316 stainless steel, making it ideal for waste heat recovery and industrial heating systems.
• Strong and reliable fin bondingHighfrequency welded (HFW) serrated fins form a metallurgical bond with the base tube, ensuring low contact resistance, high bonding strength, and resistance to fin peeling or loosening during longterm operation.
• Uniform structure & stable performancePrecise control of fin height, thickness, pitch, and serration geometry ensures consistent heat transfer, low flow resistance, and reliable longterm performance under thermal cycling.
• Good mechanical properties & processabilityASTM A213 T22 seamless tube combines good ductility, weldability, and heat treatment stability, supporting bending, expansion, and installation in complex heat exchanger layouts.
• Wide adaptability to harsh environmentsSuitable for elevated temperatures, moderate corrosion, and thermal fatigue conditions in industries such as power generation, oil refineries, petrochemicals, and waste heat recovery.
• Optimized structure for compact heat exchangersThe serrated fin design increases effective heat exchange area without excessive volume, allowing more compact and efficient heat exchanger design.

4. Applications

• Utility & Industrial Boilers (Superheaters, Reheaters, Economizers)
• Heat Recovery Steam Generators (HRSG)
• Waste Heat Recovery Units (WHRU)
• Fired Heaters & Reformers in Refineries
• Air Preheaters