ASTM A335 P9 Serrated Finned Tubes for Air Preheaters
ASTM A335 P9 Serrated Finned Tubes for Air Preheaters are engineered for high-temperature heat recovery systems operating under demanding service conditions. Manufactured with an ASTM A335 P9 seamless alloy steel base tube and carbon steel (CS) serrated fins, these finned tubes provide an excellent balance of thermal efficiency, mechanical strength, and long-term reliability.
The serrated fin design interrupts the airflow boundary layer, increasing turbulence and improving heat transfer performance compared with solid fin designs. This construction also helps reduce dust accumulation, making it suitable for flue gas applications where fouling is a concern.
These finned tubes are widely used in air preheaters, economizers, waste heat recovery units, and industrial heat exchangers where operating temperatures exceed the capabilities of conventional carbon steel tubes.
- ASTM A335 P9 seamless alloy steel base tube for elevated temperature service
- Carbon steel serrated fins with excellent heat transfer performance
- Improved thermal efficiency through enhanced gas-side turbulence
- Reduced fouling and better self-cleaning characteristics
- Suitable for continuous high-temperature flue gas applications
- Excellent resistance to oxidation, creep, and thermal fatigue
- Available in customized dimensions and fin configurations
- Manufactured under strict quality control procedures
ASTM A335 P9 serrated finned tubes are commonly installed in high-temperature heat recovery equipment, including:
- Air Preheaters (APH)
- Heat Recovery Steam Generators (HRSG)
- Boiler Economizers
- Waste Heat Boilers
- Refinery Fired Heaters
- Petrochemical Process Heaters
- Power Plant Heat Recovery Systems
- Industrial Waste Heat Recovery Units
- Cement Plant Heat Recovery Equipment
- Steel Plant Flue Gas Heat Exchangers
| Item | Standard Range |
|---|---|
| Base Tube OD | 25.4–63.5 mm (1"–2-1/2") |
| Base Tube Wall Thickness | 2.5–8.0 mm |
| Tube Length | Up to 18,000 mm |
| Fin Height | 8–25 mm |
| Fin Thickness | 0.8–1.5 mm |
| Fin Pitch | 3.5–10 mm |
| Fin Material | Carbon Steel (CS) |
| Base Tube Material | ASTM A335 P9 |
| Manufacturing Process | High Frequency Resistance Welded (HFW/HFW) |
Custom dimensions are available upon request.
| Element | Content (%) |
|---|---|
| Carbon (C) | 0.15 max |
| Manganese (Mn) | 0.30–0.60 |
| Silicon (Si) | 0.25–1.00 |
| Chromium (Cr) | 8.00–10.00 |
| Molybdenum (Mo) | 0.90–1.10 |
| Phosphorus (P) | 0.025 max |
| Sulfur (S) | 0.025 max |
Values are based on ASTM A335 material requirements.
| Property | Value |
|---|---|
| Tensile Strength | ≥ 585 MPa |
| Yield Strength | ≥ 415 MPa |
| Elongation | ≥ 20% |
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