A335 P22 Serrated Finned Tubes with CS Fins for HRSG & Heat Recovery Systems

Serrated Finned Tubes - A335 P22 Base Tube, Carbon Steel Fins | Boiler & Heater Application

1. Product Introduction: Serrated Finned Tubes

Our serrated finned tubes combine the high-temperature strength of chrome-moly alloy P22 base pipes with the cost-effective thermal conductivity of carbon steel fins, engineered for demanding applications in power plants, refineries, and chemical processing units.

2. Metallurgical Synergy: Base Tube & Fin Chemistry

2.1 Base Tube (A335 P22) – High-Temperatre Cuhampion

Chemical Composition per ASTM A335:

2.2 Carbon Steel Fins – Cost-Effective Durability

Typical Composition (ASTM A570):

3. Advanced Manufacturing Process

3-Step Quality-Controlled Production:

1. Fin Formation: Cold-rolled CS strip punched into serrated fins (fin height tolerance: ±0.15mm)

1. High-Frequency Welding: Fins bonded to P22 base tube at 1150°C ±20°C under inert gas shield

1. Post-Weld Treatment: Stress relieving at 650°C for 2 hours (per ASME Sec. VIII)

Critical Process Controls:

• Weld penetration depth: ≥75% of fin thickness

• Shear strength: ≥250 MPa (tested per EN 1390)

• Eddy current testing: 100% tube inspection

4. Dimensional Precision & Tolerances

5. Critical Application Domains

6. Competitive Advantages & Proven Performance

• Thermal Efficiency: 25-40% higher HTC than plain tubes (HTRI field data)

• Corrosion Resistance: P22 base withstands H₂S partial pressure >0.05 psi

• Mechanical Integrity: Creep rupture strength >80 MPa at 550°C (per NIMS data)

• Field Experience: 15+ years service life in FCCU air preheaters (documented cases)