Wrap On Knurled L Fin Tube ‘KL’ Fin

Here is the professional of the provided content on KL-Type Fin Tubes with Wrap-on Knurling:

‌KL-Type Fin Tubes (Wrap-on Knurled Finned Tubes)‌
The KL-Type fin tube is a wrapped fin tube that enhances heat transfer performance through a specialized knurling process. Its core feature involves machining knurled patterns onto the base tube surface before winding the fin strip, forming a tightly wrapped structure. Key technical characteristics and applications are as follows:

I. Wrap-on Knurled Finned Tubes Structural & Process Features

1. ‌Pre-Knurled Base Tube‌
   Before aluminum strip winding, specialized equipment rolls axial or helical grooves/textures onto the base tube (carbon steel, stainless steel, etc.). This process increases the contact area between the fin and base tube by approximately 50%. During winding, mechanical force embeds the fin root into the grooves.
2. ‌Secondary Rolling Reinforcement‌
   After winding, the fin root undergoes secondary rolling to further eliminate gaps and enhance tube-fin bond strength. This “wrapped” structure withstands repeated thermal cycling without loosening.

II. Wrap-on Knurled Finned Tubes Performance Advantages

1. ‌High-Efficiency Heat Transfer‌
   Contact thermal resistance is reduced by over 30% compared to standard L-Type fin tubes, significantly improving the heat transfer coefficient. Experimental data shows KL-Type provides 15%-20% higher heat dissipation than L-Type under identical conditions.
2. ‌High-Strength Bonding‌
   The knurled grooves create a mechanical interlock structure, achieving pull-off resistance up to 1.5 times that of conventional products, making it suitable for vibrating environments.
3. ‌Temperature & Pressure Resistance‌
   Maximum continuous operating temperature reaches 250°C (280°C peak), with pressure resistance up to 3.2MPa, meeting most industrial requirements.

III. KL-Type Fin Tubes Typical Application Fields

IV. Technical Limitations

Note: Aluminum fins may corrode in strong acid/alkaline environments. Production costs are ~20% higher than standard wrapped fin tubes37. Current processes are primarily suitable for tube diameters of Φ25-Φ89mm; achieving uniform knurling on larger diameters remains a technical challenge.