ASTM A335 P9 Alloy Steel Studded Fin Tube For HVAC Systems
1. What is ASTM A335 P9 Studded Fin Tube?
ASTM A335 P9 Studded Fin Tube is a high-temperature solution engineered for severe sulfidation and ash erosion environments. It combines a seamless chromium-molybdenum alloy steel base tube (ASTM A335 P9, UNS S50400) with carbon steel stud-type fins resistance-welded perpendicularly to the surface. This robust design maximizes heat transfer area while preventing ash buildup, delivering 5x longer sulfidation resistance than carbon steel in refinery heaters, coker units, and waste incinerators operating up to 600°C (1,112°F).
2. Chemical & Mechanical Properties
Dimensional Specifications:
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Bare Tube Diameter:25-219mm |
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Fin Height::5-35mm |
Fin Thickness: Φ5-20mm |
Fin Pitch: 8-30mm |
Tube Ends: Plain Ends / Beveled Ends |
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No Fin Area (Both Ends): As Customer’s Request and Drawing |
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Chemical Composition (%)
| ASTM A335 P9 Chemicial Composition(%) | |||||||
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Element |
C |
Si |
Mo |
P |
Si |
Cr |
S |
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Range |
≤ 0.15 |
0.25-1.00 |
0.90-1.10 |
≤ 0.025 |
≤0.030 |
8.0–10.0 |
<0.025 |
Mechanical Properties
| ASTM A335 P9 Mechanical Properties | ||||
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Tensile Strength |
Yield Strength |
Elongation |
Hardness |
Max Service Temp. |
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≥415 MPa |
≥205MPa |
≥30% |
≤ 179 HB |
600°C (1112°F) |
3. Key Applications & Competitive Advantages
● Refinery Heaters: Convection sections in crude/vacuum distillation units (NACE RP0472 compliant).
● Delayed Cokers: Transfer line exchangers for 500°C+ vapors.
● Waste-to-Energy: Boiler tubes for municipal solid waste (MSW) incinerators.
● Coal-Fired Plants: Economizers handling >50g/Nm³ fly ash.
● Chemical Processing: Sulfuric acid regeneration heaters.
4.Why choose ASTM A335 Gr.9 Studded Fin Tube:
A:Company Competitiveness:
Yuhong Holding Group has more than 35 years experience for steel pipe and tube , fin tube , main application for Petrochemical , Oil refinary, Furnace, heating, boiler, heat exchanger, air cooler,.., till now YUHONG brand products already exported more than 85 countries, which like UK, ITALY, SPAIN , USA, MEXICO , COLOMBIA , BRAZIL, SAUDI ARANBIA , OMAN, QATAR, U.A.E, KOREA, ...., YUHONG brand already won good reputation in the market.
B:Product Competitiveness:
● Ash Self-Cleaning: Stud spacing reduces fouling by 60% vs. helical fins (EPRI Study).
● 10-Year Lifespan: Withstands cyclic operation per API 530.
● Cost Saving: 35% lower OPEX than refractory-lined carbon steel.
● Rapid Delivery: 50+ standard sizes (OD 25–152mm) in stock.
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