ASME SA213 T11 Serrated Fin Tube For Economizers and Air Heater

Product Specification

ASME SA213 T11 Serrated Fin Tube Base Tube:

• The core of this product is the T11 alloy steel tube, a seamless tube specifically designed for high-temperature and high-pressure service.
• Standard Compliance: Conforms to ASME SA213/ASTM A213, the standard for seamless ferritic alloy-steel boiler, superheater, and heat-exchanger tubes.
• Key Material Properties:
• Excellent high-temperature strength: Good resistance to oxidation and creep, suitable for temperatures up to about 600°C.
• Good mechanical properties: Minimum tensile strength of 415 MPa and yield strength of 205 MPa.
• Seamless construction: Provides higher strength and reliability under pressure compared to welded tubes.

ASME SA213 T11 Serrated Fin Tube Features and Principles

• Principle of Operation: The core function is to drastically increase the heat transfer surface area. The serrations (cuts in the fins) further promote turbulent airflow across the tube surface. This turbulence disrupts the insulating boundary layer of gas or fluid, significantly improving heat exchange efficiency and helping to reduce ash and dust buildup.
• Manufacturing and Key Features: High-Frequency Resistance Welding: Fins are typically welded onto the base tube using processes like high-frequency resistance welding for strong bonding.
• Rigorous Quality Control: Manufacturing involves strict tests like pull-off force tests (requiring strength >200 MPa or causing tube tearing), bending tests, and visual inspections to ensure weld integrity. The heat-affected zone on the base tube is kept very small (≤ 0.5mm).
• Precision Dimensions: These tubes are built with high precision, with tight tolerances on fin spacing (±0.2mm), fin-to-tube verticality (±1°), and flatness.

ASME SA213 T11 Serrated Fin Tube Common Applications

Serrated fin tubes made with SA213 T11 base material are used in equipment where efficient heat recovery from hot gases is critical. Common applications include:

• Heat Recovery Steam Generators (HRSG)
• Economizers for boilers
• Waste Heat Boilers in industrial plants
• Air Heaters
• Catalytic cracking units and other heat exchangers in petrochemical refineries

ASME SA213 T11 Serrated Fin Tube Advantages and Services

Combining the T11 base tube with a serrated fin design offers several key advantages.

• Enhanced Heat Transfer Efficiency: The primary advantage, leading to more compact heat exchanger designs and improved energy efficiency.
• Reduced Fouling: The serrated design helps minimize ash deposition and is often available in configurations like the H-type fin tube, which has good anti-fouling characteristics and a long service life (over 10 years).
• High-Temperature and Pressure Resistance: The SA213 T11 base material ensures mechanical integrity and oxidation resistance in demanding environments.
• Services: Manufacturers often provide customized processing (such as bending to requirements) and national distribution services.

ASME SA213 T11 Serrated Fin Tube Potential FAQs

• What is the difference between a serrated fin and other fin types? Unlike solid fins, serrated fins have gaps that create more edges, disrupting airflow more effectively to enhance turbulence and heat transfer. H-type fins are another variant designed for structural stability and reduced ash accumulation.
• Why is the SA213 T11 base tube heat-treated? The T11 material must undergo heat treatment (e.g., normalizing and tempering) to achieve the required mechanical properties (strength, ductility) and a stable microstructure for high-temperature service.
• What are the key checks for fin tube quality? Critical checks include weld strength (pull-off test), fin spacing accuracy, and the absence of cracks after bending the fins.