KL Type Finned Tube, Knurled Finned Tubes

What is Knurled Finned Tubes?

KL Fin Tubes also called knurled finned tubes. The fin is wrapped around the tube and the foot is rolled into the outer surface of the pre knurled tube and secured at each end. Gives good surface protection to the tube and improved heat transfer compared to the L or LL type fin. This finned tube is used for moderate temperature cooling applications.

Knurled finned tubes are basically identical to the Wrap-On fin and produced with a combination of Wrap-On and Embedded. The fins are manufactured from strip which is preformed into an accurately controlled L shape similar to the L type, rolled into a taper which causes it to knurled. Then continuously helically wound under tension onto the tube. The fin wrapped around the tube. The base tube is knurled by a rotating tool, then the foot of the fin is knurled into the base tube, which provide a tight bond with increased thermal performance. Providing the correct fin strip is used the foot of one fin butts up against the next fin and there is no gap between the fins. This gives some corrosion protection to the tube. The fins are secured at each end to prevent unwinding in a similar way as L fins.

The fin is wrapped around the tube and the foot is rolled into the outer surface of the pre knurled tube and secured at each end. Gives good surface protection to the tube and improved heat transfer compared to the L or LL type fin tube. KL -Foot tension wound finned tubes are commonly used in applications with metal Maximum Operating Temperature- up to 320°C (608°F)

Advantages of the KL Fin Tubing/Knurled Finned Tubes:

1. Tube protected against corrosion
2. Medium temperature applications
3. Increased fin to tube bond
4. Greater thermal contact than standard L fin
5. Added heat transfer performance due to the knurling
6. Increased atmospheric corrosion protection of the core tube
7. Good stability
8. Resistant to vibrations
9. May be used at temperature up to 320°C (608°F)
10. Unique combination of high thermal performance and stresses resistance with atmospheric corrosion protection

KL finned tubes can favorably replace any type of finned tubes Manufactured method is exactly as the L finned tube except that the base tubes are knurled before application of these fin foot. After application, the fin foot is knurled into the corresponding knurling on the base tube thereby enhancing the bond between the fin and tube, resulting in improved heat transfer characteristics.

Knurled Finned Tubes materials: 

Tube Material: Any material available, such as Carbon Steel/ Carbon Alloy Steel/Stainless Steel/ Nickel Alloys/ Copper/Copper Alloys/Titanium, A179, A192, A210, stainless tube A269/A213 T5 T11 T22 304 316/316L

Knurled Finned Tube Fin Material : Aluminium or Copper

Knurled Finned Tubes Size: 

Knurled Finned Tube Diameter:1/2” (12.7mm) to 2” (50.8mm)

Knurled Finned Tube Wall Thickness:> 0.049” (1.244mm) depending on tube material and outside diameter

Knurled Finned Tube Fin Heights:1/4” (6.35mm) to 1” (25.4mm)

Knurled Finned Tube Fin Pitches:5 to 12 fins per inch

Knurled Finned Tube Fin Strip Thickness:0.012” (0.30mm) to 0.020” (0.50mm)

The fin is wrapped around the tube and the foot is rolled into the outer surface of the pre knurled tube and secured at each end. Gives good surface protection to the tube and improved heat transfer compared to the L or LL type fin. This finned tube is used for moderate temperature cooling applications.

Knurled Finned Tube upper Temperature limit: 250°C