Eight Main Types of Welded Finned Tubes

In the field of industrial heat exchange, finned tubes, as a highly efficient heat transfer enhancement element, are widely used in equipment such as boilers, heat exchangers, and air coolers. Among the various methods of connecting fins to the base tube, welding processes have become the preferred solution in many scenarios due to their high bonding strength, low thermal resistance, and wide applicability to diverse operating conditions.

After in-depth research, there are currently eight main types of welded finned tubes. Today, we will unveil their structures and characteristics one by one.

1. Laser Welded Finned Tubes
Laser welding is a precision welding technology that has developed rapidly in recent years. It uses a high-energy laser beam to instantly melt and weld metal fins onto the surface of the base tube.

Characteristics:
Extremely Small Heat-Affected Zone: Minimal damage to the base tube material, especially suitable for special materials like stainless steel and titanium.
Aesthetic and Strong Weld Seam: High welding strength and extremely low contact thermal resistance.
Thin and Lightweight Fins: Enables processing of thinner, denser fins, suitable for compact heat exchangers.

Click here for more details: https://www.lordfintube.com/laser-welded-carbon-steel-finned-tube_1290.html

2. High-Frequency Welded Finned Tubes
This is one of the most widely used types of welded finned tubes. It utilizes the skin effect and proximity effect of high-frequency current to continuously spiral and weld a steel strip onto the steel tube.

Characteristics:
High Production Efficiency: Suitable for mass production.
Excellent Heat Transfer Performance: High weld integrity, virtually no contact thermal resistance.
Wide Applicability: Mainly used in carbon steel and stainless steel applications like boiler economizers and air coolers.

Classification Based on Fin Shape:
High-frequency welded finned tubes can be mainly divided into the following two types based on the fin shape:
Solid Finned Tubes: The fins are a complete, continuous spiral with a smooth, unbroken surface. This structure offers the maximum heat transfer area and high thermal efficiency, suitable for clean gas environments such as air coolers and convection sections of heating furnaces in general working conditions.
Serrated Finned Tubes: The fin edges are cut with uniform notches or serrations. This serrated design effectively disrupts the fluid boundary layer, enhancing turbulence and thus further increasing the heat transfer coefficient. Additionally, it can reduce the surface tension of high-viscosity fluids and slightly mitigate ash fouling problems, making it suitable for dust-laden flue gas applications or situations requiring enhanced heat transfer.

3. Square H/HH Type Finned Tubes
This is a relatively special welded structure, typically using submerged arc welding or gas shielded arc welding to symmetrically weld rectangular or square steel plates (H-type) onto the base tube. If two tubes are connected in parallel with fins, it forms the HH type.

Characteristics:
Strong Self-Cleaning Ability: The square fin structure allows flue gas to flow smoothly along the length, making it less prone to ash deposition.
High Rigidity: Can withstand harsh operating conditions with high flue gas velocities or where soot blowing is required.
Application Scenarios: Commonly found in power plant boilers and waste heat recovery systems.

4. Studded Pipes
Studded pipes (also known as pin pipes) involve welding cylindrical metal studs (pins) vertically onto the surface of the base tube using resistance welding or manual arc welding.

Characteristics:
Vibration Resistance and Wear Resistance: The stud structure is robust, making it very suitable for environments with vibrations.
Enhanced Disturbance: Significantly disrupts the fluid boundary layer, resulting in notable heat transfer enhancement.
Typical Applications: High-temperature and high-pressure situations such as convection sections of cracking furnaces and heating furnaces.

Click here for the available sizes of studded pipes: https://www.lordfintube.com/studded-tubes_1163.html

5. Brazed Elliptical Finned Tubes
This type of finned tube typically uses an elliptical tube as the base tube. Pre-punched rectangular or circular fins are slipped over the tube, and the entire assembly is joined in a brazing furnace. The brazing filler metal melts and fills the gaps between the fins and the tube wall.

Characteristics:
Dense Connection: The brazing material has good fluidity, forming a uniform and sound joint.
Advantages of Elliptical Tubes: Elliptical tubes offer lower air-side pressure drop, and they are less prone to deformation during brazing.
Applicable Materials: Commonly used for combinations like copper-steel, copper-copper, and stainless steel.

Available materials for Longitudinal finned tubes: https://www.lordfintube.com/LFW-type-fin-tube_1158.html

6. Longitudinal Finned Tubes
Unlike the previously mentioned spiral fins, the fins in longitudinal finned tubes are welded parallel to the axis of the base tube, typically using TIG welding or high-frequency welding.

Characteristics:
Low Pressure Drop: Fluid flows longitudinally along the fins, resulting in minimal resistance loss.
Good Condensation Performance: Facilitates the draining of condensate along the fins, often used in vertical heat exchangers.
Typical Applications: Inner tubes of double-pipe heat exchangers, gas-to-gas heat exchangers.

7. Brazed Single-Row Flat Tubes
This is a structure specifically designed for particular heat exchange modules. The single-row large flat tube itself is flattened, and fins or turbulators are welded onto its flat surfaces or sides through brazing.

Characteristics:
Compact Structure: The large flat tube increases the flow cross-sectional area, reducing the number of tube rows required.
Efficient Heat Conduction: The flat surface provides a large contact area for welding, resulting in a short heat conduction path.
Application Fields: HVAC systems, heat pumps, and some specialized chemical cooling processes.

There is a fixed size for single row flat finned tubes. Visit the following link to learn more: https://www.lordfintube.com/single-row-flat-fin-tube_1145.html

8. Inner Finned Tubes
Welding inner finned tubes is more challenging. It involves fixing the fin structure onto the inner wall of the pipe through welding. Due to the confined space, special methods like drawn-profile welding or vacuum brazing are typically employed.

Characteristics:
Enhanced In-Tube Heat Transfer: Specifically designed to enhance heat transfer for fluids inside the tube (e.g., high-viscosity media).
Increased Heat Transfer Area: Maximizes the surface area within the limited internal space.
Specialized Applications: Mainly used in hydraulic oil coolers, compressed air dryers, and certain chemical reactors.

The following website link will show you more acknowledges about inner finned tubes: https://www.lordfintube.com/inner-finned-tube_1106.html

Each of the eight types of welded finned tubes mentioned above has its own unique skills. Laser welded and High-frequency welded tubes dominate the general market due to their efficiency and quality; among them, high-frequency welded tubes, through different designs like solid and serrated fins, can more precisely match working conditions involving clean or dust-laden flue gas. H/HH type and studded tubes excel in harsh conditions requiring wear resistance and easy cleaning, while brazed types and inner finned tubes are indispensable in precision and special heat exchange applications.

When selecting the type of finned tube, we need to comprehensively consider factors such as medium characteristics (corrosiveness, abrasiveness, cleanliness), temperature and pressure, allowable pressure drop, and cost budget. Only by choosing the right finned tube can the heat exchange equipment achieve its optimal performance.

I hope this overview helps you gain a clearer understanding of the types of welded finned tubes available. If you want to learn more, feel free to leave a message for discussion!

Company Name: Shanghai T.S. Industrial Co. Ltd
Contact Name: Miss Estela
Contact Number: 0086-021-66030009
Address: No.2, Lane 1588 Youyi Road, Baoshan, Shanghai, The P. R. of China. Post. 201999
Email: estela@lordfintube.com
Website: https://www.lordfintube.com/

Shanghai T.S. Industrial Co., Ltd is a leading company specializing in the production of finned tubes, tube sheet, U bend tubes, and helical coiled pipe used in heat exchangers, boiler economizers, coolers, and heaters. Our focus is on supplying custom fin tubes, finned pipes, and tube sheets in various material configurations to enhance heat transfer rates and reduce operating costs. With our advanced production capabilities and commitment to quality, we deliver innovative and efficient solutions tailored to meet the specific needs of our clients in the heat exchanger and boiler industries.

This release was published on openPR.