ODM / OEM 18 Years Factory Finned Tube Types-L LL KL Fin Tubes

Wound fin tubes are divided into L-type, LL-type and KL-type fin tubes, according to their processing technology, characteristics, and use environment.

Here is the professional English translation of the specifications for L-type, LL-type, and KL-type finned tubes:

I. Core Classification & Process Characteristics

1. ‌L-Type Finned Tubes‌

   • ‌Process‌: Aluminum or copper fins folded into an L-shape and spirally wound onto the base tube under tension．
   • ‌Performance‌: Fin-to-tube bonding relies on mechanical tension. Maximum operating temperature: ‌150°C‌．
   • ‌Applications‌: Heating radiators, low-temperature heat exchange systems (e.g., food drying equipment)．

2. ‌LL-Type Finned Tubes‌

   • ‌Process Upgrade‌: Based on L-type, fins fully cover the base tube surface at the root, minimizing gaps．
   • ‌Enhanced Performance‌: Improved corrosion resistance; max. operating temperature: ‌170°C‌．
   • ‌Use Cases‌: Petrochemical/power industry air coolers and corrosion-prone environments．

3. ‌KL-Type Finned Tubes‌

   • ‌Core Process‌: Base tube pre-knurled → fins wound → root re-rolled, increasing contact area by ‌50%‌．
   • ‌Advantages‌:
     • Lower contact thermal resistance → ‌superior heat transfer‌ vs. L/LL types；
     • Withstands thermal cycling → no loosening; max. operating temp.: ‌250°C‌．
   • ‌Typical Applications‌: High-temperature/pressure scenarios (e.g., power plant waste heat recovery, industrial boilers)．

II. Key Performance Comparison

III. Selection Guidelines

• ‌Corrosion Priority‌: Humid/corrosive environments (e.g., marine, chemical) → ‌LL-type‌；
• ‌High-Temp. Scenarios‌: Steam exchange/waste heat recovery (>200°C) → ‌KL-type‌；
• ‌Cost Efficiency‌: Low-temperature civil heating → economical ‌L-type‌．

Note: All types use carbon steel/stainless steel/copper base tubes with aluminum/copper fins. Material selection must align with medium compatibility (e.g., pH)．