ASTM A335 P11 Base Tube Composition
| Grade | UNS Designation | C | Mn | P | S | Si | Cr | Mo |
| P11 | K11597 | 0.05-0.15 | 0.30-0.60 | 0.025 | 0.025 | 0.5-1.00 | 1.00-1.50 | 0.44-0.65 |
ASTM A335 P11 Serrated Fin Tube Application
1. Power Generation
- Boilers: Used in water walls, economizers, and steam drums for efficient heat exchange.
- Superheaters/Reheaters: Transfers heat to steam while withstanding temperatures up to 580°C (1,076°F).
- Heat Recovery Systems: Captures waste heat from exhaust gases in combined-cycle plants.
2. Petrochemical & Refining
- Catalytic Reforming Units: Facilitates heat transfer in reactors and furnaces.
- Crude Oil Heaters: Preheats crude oil before distillation.
- Hydrogenation Reactors: Manages heat in high-pressure hydrogen environments.
3. Chemical Processing
- Process Heaters: Heats chemicals in reactors or distillation columns.
- Sulfur Recovery Units (SRUs): Used in Claus process heat exchangers.
- Ethylene Crackers: Handles heat in pyrolysis furnaces.
4. Industrial Heating Systems
- Thermal Oil Heaters: Transfers heat in systems using synthetic or mineral oils.
- Air Preheaters: Improves boiler efficiency by preheating combustion air.
- Furnace Convection Sections: Enhances heat recovery in industrial furnaces.
5. Oil & Gas
- Gas Processing Plants: Cools natural gas streams.
- Refinery Heaters: Used in fired heaters and reformers.
- Coker Units: Manages heat in delayed coking processes.
ASTM A335 P11 Serrated Fin Tube Strength
1. Mechanical Properties
- Tensile Strength: ≥415 MPa (60,000 psi).
- Yield Strength: ≥205 MPa (30,000 psi).
- Elongation: ≥30% (in 50 mm).
- Hardness: ≤197 HBW (Brinell Hardness).
2. Moderate High-Temperature Performance: Suitable for up to 580°C (1,076°F).
3. Cost-Effective: More economical than higher-grade alloys (e.g., P9, P91).
4. Improved Heat Transfer: Serrated fins boost efficiency by 15–30% over plain fins.
5. Weldability: Easier to weld than high-chromium steels (no stringent pre/post-weld heat treatment required).
