High Grade Welded Square Fin Tubes are suitable for applications in heat transfer equipment that are subject to high temperatures, thermal cycling and challenging process conditions. The extended heat-transfer surfaces resulting from their H-shaped fin profile, combined with well-defined gas-flow passages around the tube, makes them a valuable addition to a heat exchanger. The pressure tube and fin can be made of alloy steels like P11, P22 and T91, or nickel-based alloys like Inconel 600/625, Incoloy 800/825 and Monel 400 if higher temperatures are required and/or certain corrosion or oxidation needs exist. The resistance-welded fin to tube joint ensures secure connection and stable performance under challenging conditions. The dimensions of the fin, the size of the tubes, their grade of materials and the type of welding can be made as per the requirement of the project. Amardeep Steel is a seasoned manufacturer, supplier of High Grade Welded Square Fin Tubes in India.
Technical Data
Specifications of High Grade Welded Square Fin Tubes
Specification Parameter | Technical Detail / Value |
|---|---|
Fin Type | Welded Square Fin (H-Type / Double H-Type) |
Base Tube Materials | Alloy Steel ASTM A213 / A335 (P5, P9, P11, P22, P91/T91), Inconel (600, 625), Incoloy (800, 825, 800H), Monel 400 |
Fin Materials | Matching High Chrome / High Nickel Alloy Strip, Alloy Steel, Inconel 600/625, Incoloy 800/825, Monel 400 |
Bare Tube Outer Diameter (OD) | 25.4 mm to 76.2 mm (1.0" to 3.0") |
Minimum Wall Thickness | 2.11 mm to 8.0 mm (depending on pressure rating and ASME code requirements) |
Fin Size (Square Height/Width) | 40 mm x 40 mm to 120 mm x 120 mm |
Fin Thickness | 1.5 mm to 4.0 mm |
Fin Pitch / Spacing | 9 mm to 30 mm (30 to 110 fins per meter) |
Welding Process | High-Frequency Electric Resistance Welding (HFW) with protective inert shielding gas |
Documentation & Testing | EN 10204 3.1 / 3.2 MTC, PMI Testing, Radiographic/Ultrasonic Weld Inspection, Hydrostatic Testing |
Chemical Compositions of High Grade Welded Square Fin Tubes
Grade / Alloy | Carbon (C) | Chromium (Cr) | Nickel (Ni) | Moly (Mo) | Iron (Fe) | Other Elements |
|---|---|---|---|---|---|---|
Alloy Steel T11 / P11 | 0.05 - 0.15 | 1.00 - 1.50 | — | 0.44 - 0.65 | Balance | Si: 0.50-1.00, Mn: 0.30-0.60 |
Alloy Steel T22 / P22 | 0.05 - 0.15 | 1.90 - 2.60 | — | 0.87 - 1.13 | Balance | Mn: 0.30-0.60, Si: 0.50 max |
Alloy Steel T91 / P91 | 0.08 - 0.12 | 8.00 - 9.50 | 0.40 max | 0.85 - 1.05 | Balance | V: 0.18-0.25, Nb: 0.06-0.10 |
Inconel 600 | 0.15 max | 14.0 - 17.0 | 72.0 min | — | 6.00-10.00 | Cu: 0.50 max, Mn: 1.00 max |
Inconel 625 | 0.10 max | 20.0 - 23.0 | 58.0 min | 8.00 - 10.0 | 5.00 max | Nb+Ta: 3.15-4.15, Al: 0.40 max |
Incoloy 800 / 800H | 0.05 - 0.10 | 19.0 - 23.0 | 30.0 - 35.0 | — | 39.5 min | Al: 0.15-0.60, Ti: 0.15-0.60 |
Incoloy 825 | 0.05 max | 19.5 - 23.5 | 38.0 - 46.0 | 2.50 - 3.50 | 22.0 min | Cu: 1.50-3.00, Ti: 0.60-1.20 |
Monel 400 | 0.30 max | — | 63.0 min | — | 2.50 max | Cu: 28.0-34.0, Mn: 2.00 max |
High Grade Welded Square Fin Tubes Mechanical Properties
Material Grade | Tensile Strength, Min (MPa) | Yield Strength 0.2% Proof (MPa) | Elongation 2" / 50mm (%) |
|---|---|---|---|
Alloy Steel P11 / T11 | 415 | 205 | 30 |
Alloy Steel P22 / T22 | 415 | 205 | 30 |
Alloy Steel P91 / T91 | 585 | 415 | 20 |
Inconel 600 | 550 | 240 | 30 |
Inconel 625 | 760 | 415 | 30 |
Incoloy 800 / 800H | 520 | 205 | 30 |
Incoloy 825 | 586 | 241 | 30 |
Monel 400 | 480 | 170 | 35 |
Dimensions Chart of High Grade Welded Square Fin Tubes
Bare Tube OD (mm) | Fin Dimension (mm) | Fin Thickness (mm) | Fin Spacing (mm) | Typical High Grade Application |
|---|---|---|---|---|
38.1 mm (1.5") | 65 x 65 mm | 2.0 - 3.0 mm | 12 - 20 mm | HRSG Superheaters (P11 / P22) |
50.8 mm (2.0") | 80 x 80 mm | 2.5 - 3.5 mm | 15 - 25 mm | High Temp Reheaters (T91 / Incoloy 800H) |
60.3 mm (2.37") | 100 x 100 mm | 3.0 - 4.0 mm | 15 - 30 mm | Chemical Waste Heat Boilers (Inconel 625) |
76.2 mm (3.0") | 120 x 120 mm | 3.0 - 4.0 mm | 18 - 30 mm | Offshore / Marine Boilers (Monel 400) |
Working with Inconel, Incoloy or Monel for a high-temperature reheater or waste heat boiler? Share your design temperature and pressure class and we'll confirm the right fin alloy and weld spec.
Talk to Our Alloy SpecialistsApplications and Industrial Uses of High Grade Welded Square Fin Tubes
- High-Temperature Boilers
- Superheaters
- Reheaters
- Heat Recovery Steam Generators (HRSG)
- Waste Heat Boilers
- Refinery Process Heaters
- Petrochemical Furnaces
- Industrial Heat Recovery Systems
Frequently Asked Questions
What are High Grade Welded Square Fin Tubes?
High Grade Welded Square Fin Tubes are tubes with H-shaped or square fins welded to the outer surface to increase heat-transfer area and support demanding high-temperature service.
How are High Grade Welded Square Fin Tubes manufactured?
They are manufactured by resistance-welding shaped steel or alloy fins continuously to the outer surface of the base tube.
What are the advantages of H-Type and HH-Type Fin Tubes?
They provide increased heat-transfer area, defined gas-flow passages, good fin attachment, and resistance to demanding operating conditions.
What materials are used for High Grade Welded Square Fin Tubes?
Common materials include alloy steels such as P11, P22, and T91, along with nickel alloys such as Inconel, Incoloy, and Monel.
Are High Grade Welded Square Fin Tubes suitable for boilers?
Yes. They are suitable for boiler sections exposed to elevated temperatures and demanding heat-transfer conditions.
Can High Grade Welded Square Fin Tubes be customized?
Yes. Tube material, fin material, tube dimensions, fin size, fin density, and tube length can be customized according to project requirements.
