ASTM A106 Gr.B Studded Tube with CS Fins for Economizers and Air
Preheaters
An ASTM A106 Gr.B Studded Tube with CS (Carbon Steel) Fins is a
specialized type of heat exchanger tube designed for
high-efficiency heat transfer in demanding industrial applications.
Here’s a detailed breakdown:
1. Base Tube: ASTM A106 Gr.B
(1) Chemical Composition (ASTM A106 Gr.B)
| Element | Composition (% Max) |
| Carbon (C) | 0.30 max |
| Manganese (Mn) | 0.29–1.06 |
| Phosphorus (P) | 0.035 max |
| Sulfur (S) | 0.035 max |
| Silicon (Si) | 0.10 min* |
| Chromium (Cr) | 0.40 max |
| Copper (Cu) | 0.40 max |
| Molybdenum (Mo) | 0.15 max |
| Nickel (Ni) | 0.40 max |
| Vanadium (V) | 0.08 max |
Notes:
Si (Silicon) improves oxidation resistance at high temps.
Low S/P reduces brittleness and improves weldability.
Mn enhances strength and hardenability.
(2) Mechanical Properties (ASTM A106 Gr.B)
| Property | Value |
| Tensile Strength | ≥ 415 MPa (60,200 psi) |
| Yield Strength | ≥ 240 MPa (35,000 psi) |
| Elongation (in 50mm) | ≥ 20% (longitudinal) |
| Hardness (Brinell) | ≤ 179 HB |
| Allowable Stress (at 400°C/750°F) | ~110 MPa (16,000 psi)* |
Notes:
High tensile strength makes it suitable for high-pressure
steam/water service.
Good ductility (≥20% elongation) prevents cracking during
fabrication.
Hardness limit ensures weldability and machinability.
Key Applications Leveraging These Properties
- Studded/Finned Tubes: Relies on A106 Gr.B’s weldability for
stud/fin attachment.
- Boiler Tubes: High yield strength resists steam pressure (up to
450°C).
- Refinery Piping: Mn/Si content aids oxidation resistance in flue
gases.
2. Studded Design
Studs (pins) are resistance-welded onto the tube’s outer surface in
a pattern (e.g., spiral, staggered).
Purpose:
Increases turbulence of flue gases/fluids, improving heat transfer.
Prevents ash/fouling buildup in dirty gas applications (e.g., waste
heat recovery).
3. Carbon Steel (CS) Fins
Fins are helical or longitudinal strips welded or embedded to
further boost surface area.
Why CS?
Cost-effective for non-corrosive environments (e.g., steam, air,
flue gases).
Compatible with high-temperature industrial processes.
4. Key Features & Advantages
| Feature | Benefit |
| Studs + Fins | 3–5x higher heat transfer vs. bare tubes |
| Seamless A106 Gr.B | No weak joints; handles high pressure |
| Carbon Steel | Affordable, durable for non-corrosive media |
| Custom Patterns | Optimized for gas flow/ash cleaning |
The ASTM A106 Gr.B Studded Tube with CS (Carbon Steel) Fins is
commonly used in heat exchangers and boilers, particularly in
applications requiring high-temperature and high-pressure
resistance. Here are its key applications:
1. Heat Exchangers (Waste Heat Recovery, Economizers, Air
Preheaters)
Used in power plants, refineries, and chemical processing
industries to recover waste heat from flue gases.
The studs (pins) and fins enhance heat transfer efficiency by
increasing the surface area.
2. Boilers (Water Tube & Fire Tube Boilers)
Suitable for high-pressure steam generation due to ASTM A106 Gr.B’s
strength.
The studded design improves heat absorption from combustion gases.
3. Petrochemical & Oil Refining Industries
Used in furnaces, reformers, and cracking units where corrosion
resistance and thermal efficiency are critical.
4. Air Coolers & Process Heaters
The finned design improves air-side heat transfer, making it ideal
for cooling and heating applications.
Key Benefits:
- High Thermal Efficiency (due to studs & fins increasing surface
area).
- High-Temperature & Pressure Resistance (ASTM A106 Gr.B is suitable
for up to 450°C).
- Durability & Corrosion Resistance (CS fins provide cost-effective
performance in non-extreme corrosive environments).
Industries Served:
- Power Generation
- Oil & Gas
- Chemical Processing
- Petrochemical
- Waste Heat Recovery Systems
