Solid Fin Tube ASTM A335 P9 Fin Material CS Heat Recovery Steam Generator

Material Specifications

Base Pipe (ASTM A335 P9):

Chromium-molybdenum (Cr-Mo) alloy steel with good high-temperature strength and corrosion resistance.

Composition: ~9% Cr, ~1% Mo, balanced with Fe.

Common applications: Power plants, refineries, high-temperature/pressure services (up to ~650°C/1200°F).

Fin Tube Construction

• Type:Solid finned tube (fins are welded or extruded integrally to the base pipe).
• Fin Attachment Methods:
• High-Frequency Welding (HFW): Most common for CS fins on alloy pipes.
• Extruded Fins: Base pipe material is deformed to create fins (rare for P9 due to hardness).
• Fin Dimensions:
• Height: 5–16 mm (typical).
• Density: 5–11 fins per inch (FPI), depending on heat transfer needs.

Performance Considerations

Thermal Conductivity: CS fins have lower heat transfer efficiency than aluminum fins but are stronger.

Temperature Limits:

P9 Pipe: Up to 650°C (1200°F).

CS Fins: Max ~400°C (750°F); beyond this, oxidation/scaling occurs.

Corrosion Resistance:

P9 resists oxidation/sulfidation; CS fins may need coatings (e.g., galvanizing, aluminizing) in corrosive environments.

Applications:

- Heat Exchangers: Boilers, economizers, air heaters.

- Process Industries: Refineries, petrochemical plants (for high-temperature gas/liquid streams).

- Power Generation: Waste heat recovery systems.

Specifications: