Copper Nickel 90 / 10 KL Footed Aluminum Fin L LL KL Type Fin Tube

Here is the professional of the technical specifications and application details for Copper-Nickel 90/10 (UNS C70600/B10) KL/L/LL/G-Type Finned Tubes, incorporating industry standards and process characteristics:

‌I. Core Material Properties‌

1. ‌Copper-Nickel 90/10 Alloy (UNS C70600)‌

   • ‌Composition‌: Cu 90%, Ni 10%, with Fe (1%-1.8%) and Mn (≤1%) added for enhanced strength. Impurities (Pb, Zn) strictly controlled at ≤0.05%‌1112.
   • ‌Performance‌:
     • Excellent seawater corrosion resistance (ideal for marine platforms/ship heat exchangers);
     • Tensile strength ≥790 MPa, high yield strength, working pressure ≤32 MPa;
     • Thermal conductivity similar to carbon steel; thermal expansion coefficient comparable to stainless steel‌.

2. ‌Base Tube Requirements‌

   • Seamless Cu-Ni tubes per ‌ASTM B466‌. Wall thickness tolerance ≤±0.05 mm; straightness deviation ≤4 mm/full length‌.
   • Alloy steel tubes require spectrochemical testing per tube to ensure compositional consistency‌.

‌II. Fin Tube Types & Manufacturing Processes‌

‌(1) KL-Type (Knurled Fin Tube)‌

• ‌Process‌: Base tube pre-knurling → Aluminum fin winding → Secondary root-rolling for enhanced bonding;
• ‌Features‌:
  • 50% larger contact area vs. L/LL types → lower contact thermal resistance;
  • Resists thermal cycling shock (operating temp ≤250°C);
  • Wrinkle-free fins with reduced fouling risk‌.

‌(2) L/LL-Type (Wound Fin Tubes)‌

• ‌L-Type‌: High-tension winding (fin roots untreated). Max temp: ‌120°C‌;
• ‌LL-Type‌: Optimized winding tension → uniform fin pitch. Max temp: ‌230°C‌;
• ‌Shared Traits‌:
  • High finned area ratio (5–8× increased surface area);
  • Fin thickness: 0.1–0.5 mm; pitch: 1.5–3 mm (design adjustable)‌.

‌(3) G-Type (Embedded Fin Tube)‌

• ‌Process‌: Spiral grooving on base tube → Aluminum strip insertion → End welding;
• ‌Advantages‌:
  • High fin rigidity → superior deformation resistance;
  • Pressure rating ≤32 MPa (ideal for high-pressure heat exchange)‌.

‌III. Key Technical Requirements‌

1. ‌Fin Parameters‌

   • ‌Height‌: 5–30 mm (typical: 15–25 mm);
   • ‌Pitch‌: 15–30 mm (too small ↑ resistance; too large ↓ efficiency);
   • ‌Thickness‌: Al fins 0.2–0.5 mm; Steel fins 0.5–0.8 mm‌.

2. ‌Tube-Fin Bond Quality‌

   • High-frequency welding fusion rate ≥90% (tested via 8-point longitudinal sectioning);
   • Embedded fins: Groove-strip gap ≤0.3 mm to prevent springback/loosening‌.

3. ‌Corrosion Protection & Maintenance‌

   • Anodized fin surfaces for enhanced marine atmospheric corrosion resistance;
   • Regular fin cleaning to maintain thermal efficiency‌.

‌IV. Typical Applications‌

• ‌Marine & Offshore‌: Ship boilers, desalination evaporators (Cl⁻ corrosion resistance);
• ‌Energy Industry‌: Power plant air coolers, waste heat recovery (KL-type for ≤250°C);
• ‌Petrochemicals‌: Oil/gas heat exchangers, FGD systems (G-type for high pressure)‌.

‌V. Selection Guidelines‌

• ‌High-Temp (>200°C)‌: Prioritize ‌KL-type‌ for thermal stability;
• ‌Corrosive Environments‌: Combine Cu-Ni base tube + Al fins (balance conductivity/corrosion resistance);
• ‌Customization‌: Provide media temp/pressure/flow rate to optimize fin pitch/height‌.