Carbon Steel LL Type Finned Tube

L/LL/KL Finned Tube Product Description:

- LL Finned Tube

Manufactured in the same way as the ‘L’ finned tube, the ‘LL’ fin has overlapping feet to completely enclose the base tube, resulting in excellent corrosion resistance. The maximum operating temperature is approximately the same as the ‘L’ fin. This type of fin commonly available in aluminum and copper. The Overlapped “L” fin design has interlocking fins that are wound together to prevent movement and separation. The fins protect the entire tube and the designation works well for the applications where corrosion is an issue.

- KL Finned Tube（Knurled Aluminum Tubing）

‘KL’ Fin Tubes are 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. The fins are manufactured from a strip of metal which is machined into an accurately controlled L shape foot, similar to the L type fin, then it is rolled into a taper causing it to curl. The tube surface is knurled by a rotating tool, then the foot of the fin is knurled into the base tube providing a tight bond that optimizes thermal transfer.

- L Finned Tube

One common type of finned tube is the ‘L’ fin. Receiving its name from the letter it creates from the cross-sectional view, the ‘L’ fin relies on maximum surface contact between fin and tube which is ensured by tension-forming a fin strip helically around the base tube.

This type of connection maximizes the heat transfer capacity and enhances the corrosion protection of the tube. The ‘L’ fin accommodates temperatures between 150 to 170 °C and comes in mainly ductile metals such as aluminum or copper which are capable of withstanding the compression around the base of the fin and allow stretching on the outside during installation.

L/LL/KL Finned Tube(Knurled Aluminum Tube) Manufacturing Process:

Applied Fin Tube is made with strip wrapped under tension around the base of the tube. Fins are welded to the base tube at the strip ends.

L/LL/KL Finned Tube(Aluminum Finned Tubes) Advantages:

- L Finned Tube

Suitable for low-temperature application.

The finning type is the most cost effective method compared to the others.

The failed fins can be easily removed during production and bare tube can be used again for finning.

There is no need for make a helical grove over the core tube.

It is possible to place the fins on a very thin-walled tube with is particularly desirable when using expensive alloys as core tube.

The tube can withstand a temperature of up to 130°C without the risk of atmospheric corrosion or thermal stress.

- LL Finned Tube

This type of finned tube is often used as an alternative to the more expensive extruded type fin in corrosive environments.

Maximum operating temperature 170ºC.

- KL Finned Tube

Corrosion-resistant Tubes

Vibration resistance

It can withstand temperatures of up to 320°C (608°F).

High thermal performance and stress resistance combined with protection from air corrosion is a one-of-a-kind combo.

Any form of finned tube can be replaced with KL."

L/LL/KL Finned Tube Properties:

Atmospheric Corrosion Resistance: OK

Mechanical Resistance: Poor

Fin Contact: Interference Fit

Fin To Tube Bond :Moderate

Heat Transfer Efficiency :Moderate

L/LL/KL Finned Tube Applications：

. the petroleum, chemical and petrochemical process industries

. natural gas treatment

. the steel industry: blast furnace and converter systems

. power generation: steam turbine exhaust condensing

- contact condensing with cooling of circulating condensate

- fossil and nuclear power plants

. air conditioning (Freon, ammonia, propane)

. incineration of household refuse

. compressor coolers, etc.

L/LL/KL Finned Tube Specifications：