High Frequency Welding Finned Tube

Sprial Welding Finned Tube

High frequency welded spiral finned tubes are generally used for petrochemical industry and mostly installed on the convection sections of fired heaters, waste heat boilers, economizers, air preheaters, and heat exchangers involving the transfer of heat from a hot fluid to a colder fluid through a tube wall.

Helical Finned Tubes provide the designer with high thermal efficiency and compact design solutions for a whole range of heat exchangers where clean flue gases are encountered. Helical finned Tubes are manufactured in both Solid and Serrated win profiles.

Helical Solid Finned Tubes are produced by helically wrapping continuous fin strip tube. The fin strip is wounded spirally onto the tube and welded continuously with a High Frequency Electrical process to the tube along the spiral root. The fin strip is held under tension and confined laterally as it is formed around the tube, thereby ensuring that the strip is in forceful contact with the tube surface.  A continuous weld is applied at the point where the fin strip first begins to bend around the tube diameter, using the gas metal arc welding process.

For a given pipe or tube size, the desired heat transfer surface area per unit length of tube can be obtained by specifying the appropriate fin height and/or number of fins per inch of length.

This welded steel finned tube configuration can be used for practically any heat transfer application, and is particularly suited to high temperature, high pressure applications.   The important features of this configuration are efficient, effective bond of fin to tube under all conditions of temperature and pressure, and ability to withstand high fin-side temperatures.

A continuous helical fin is attached to the base tube by high frequency electric resistance welding in order to give an efficient and thermally reliable bond.

Base Tube O.D
Base Tube Thickness (mm) Fin Height
Fin Thickness(mm) Fin Pitch(mm)
22 mm ~219 mm 2.0 mm ~16 mm 8 mm ~ 30 mm 0.8 mm ~ 4.0 mm 2.8 mm ~ 20 mm
Base Tube Material Fin Material Tube Length (Mtr)
Carbon Steel, Alloy Steel, Stainless Steel and Corrosion-resistance Steel Carbon Steel, Alloy Steel, Stainless Steel and Corrosion-resistance Steel ≤ 25Mtrs

H Type Finned Tube

● H type finned tube specifications

● Tube OD:25-73mm

● Tube Thk: 3.0-6.0mm

● Fin Thk: 1.5-4.0mm

● Fin Pitch: 9.0-30.0mm

● Fin Height:15.0-45.0mm

H finned tubes are widely used in utility boilers, industrial boilers, Marine power, tail of heat exchangers, economizers or waste incinerators for coal and oil installations etc.

H-economizer two rectangular fin, similar to a square, its edge length for the fluorescent tubes of 2-fold, an expansion of the heating surface.

H-economizer flash resistance welding processes used, the welding seam after the high rate of fusion, weld tensile strength, and has good thermal conductivity. H-economizer can also manufacture dual tube "double H" type fin tubes, its rigid structure, and can be applied to a longer tube row occasion.

Max. Working Temperature:  300 °C

Atmospheric Corrorsion Resisitance: OK

Mechanical Resistance: Good

Fin Material: Copper, Aluminum, carbon steel, stainless steel

Base Tube materials: Any material available, such as Carbon steel Tube, A179, A192, A210, stainless tube A269/A213 T5 T11 T22 304 316

Rectangular Finned Tubes

Single pipe square finned tubes and twin pipe rectangular finned tubes are also manufactured as per customers’ requirements. These are particularly suitable for dust laden exhaust gases, e.g. for economizers in coal and oil fired units or waste incinerators.

Studded Finned Tube

● Tube O.D.: 25~273 (mm) 1”~10”(NPS)

● Tube Wall Thk.: 3.5~28.6 (mm) 0.14”~1.1”

● Tube Length: ≤25,000 (mm)  ≤82 ft

● Stud Dia.: 6~25.4 (mm)  0.23”~1”

● Stud Height: 10~35 (mm) 0.4”~1.38”

● Stud Pitch: 8~30 (mm)  0.3”~1.2”

● Stud Shape: Cylindrical, Elliptical, Lens type 

● Finned Tubes Outside Diameter: 1" to 8"

● Stud to tube surface angle: Vertical or angular

● Stud Material: C.S. (most common grade is Q235B)

● S.S. (most common grade are AISI 304, 316, 409, 410, 321,347 )

● Tube Material: C.S. (most common grade is A106 Gr.B)

● S.S. (most common grade are TP304, 316, 321, 347 )

● A.S.(most common grade are T/P5,9,11,22,91 )

● Fin Thickness: 0.9 to 3mm

● Studded Tubes Outside Diameter: 60 to 220mm

Studded Tubes: The studs are welded to the tubes using electrical resistance welding, producing high quality welds. Studded tubes are mostly employed in preference to finned tubes in heat transfer systems in petrochemical plants, where the surface is exposed to very corrosive environment such as dirty gases or liquids. These tubes should be resistant to aggressive materials and must be cleaned frequently. Steel studded tubes are used instead of finned tubes for heat transfer in the petrochemical industry, generally in furnaces and boilers where the surface is exposed to a very corrosive environment and where very dirty gas streams require frequent or aggressive cleaning. Studded tubes are a type of metal tubes. These tubes have studs welded onto the metal tube. These studs are arranged in a specific formation throughout the length of the tube. They are often used in boilers and refineries. As they increase the surface area for higher heat transfer they are used for reheating.

Studded Tubes are applied to convection chamber of heating furnace in petrochemical industry to increase the heat transfer coefficient at the fuming side. Studded Tubes are two or three times the square of light Tubes. Due to the usage of studded Tubes, the hot strength can be obtained as the same as radiation in the reasonable design. Studded Tubes manufactured by our company adopt resistance welding method. Welding process is controlled by PLC program. Feeding motor and graduation use servo motor. Studded number can be set via the human-computer interface. The graduation parameter and compensating coefficient can be set according to technical requirements to ensure the quality and precision of products.

Application and Work Principle

1. The equipment is used exclusively for the welding of studded tubes. The studded tubes produced using this equipment is an energy-efficient heat exchange component. It is characterized by high heat transfer efficiency and high bearing pressure, and best adapted to high temperature areas. It is mainly used in waste heat recovery, petrochemical, heat exchange systems of power station boilers and other industries.

The application of studded tubes in heating furnace convection chamber of petrochemical industry can increase smoke side heat transfer coefficient. The area of studded tubes is 2 to 3 times that of light tubes. Under the condition of reasonable design, using studded tubes can obtain the same heat intensity as radiation.

2. Studded tube is an integrated heat exchange part processed using power frequency contact type resistance welding and upsetting force fusion welding.

3. The equipment adopts dual-torch metal tumor-free welding. Stepper motor is used for stud head division; and linear guide uses machine head slide. Welding precision is ensured.

4. The studded tubes welder is a mechanical-electrical integrated welder. The electric control part adopts PLC program control and man-machine interface parameter setting, and the operation is simple and reliable. The welding parameters adopt single board computer settings. Its performance is stable and convenient.

Main Technical Parameters

1. Rated input capacity: 90KVA

2. Rated input voltage: 380V±10%

3. Diameter of welded steel tubes: 60-220mm

4. Diameter of welded studs6-14mm (and other abnormally shaped studs)

5. Effective length of welded steel tubes: 13m

6.Axial spacing of welded studs: can be freely adjusted

7. Arrangement of radially welded studs: even number

8. While welding stainless steel materials, preheater is required (made by user self).

Serrated Finned Tube

Serrated fin tube is now more and more popular in the manufacturing of boiler, pressure vessel and other heat exchanger equipments. It has more advantages than other common solid fin tube, which mainly includes:

Higher heat transfer coefficient. The serrate can make the gas flow across the fins freely, enhancing the turbulent motion and improving the heat transfer effect. Researches show that serrated fin tube’s heat transfer efficiency is about 15-20% higher than common solid fin tube.

Reduce metal consume. Due to the higher heat transfer coefficient, for the same amount of heat, serrated fin tube is with less heat transfer areas, which help reduce the metal consume.

Anti-ash-deposition and anti-scaling. Due to the serrate, it is very hard for the serrated fin tube to deposit the ash and scaling.

It is more flexible to adapt to the changes of gas flow direction.

The important features of this configuration are efficient, effective bond of fin to tube under all conditions of temperature and pressure, and ability to withstand high fin side temperatures. This serrated fin configuration is even better to withstand the fin fouling if that is a problem in the application. This gives better heat transfer properties compared to solid fins.

● Technical Details

● Base Tube Details

● Tube Diameter: 20 mm OD Min to 219 mm OD Max.

● Tube Thickness: Minimum 2 mm up to 16mm

● Tube Material: Carbon Steel, Stainless Steel, Alloy Steel, Corten steel, duplex Steel, Super Duplex Steel, Inconel, High Chrome High Nickle & Incolloy, CK 20 material and some other material.

● Fin Details

● Fins Thickness: Min. 0.8 mm to Max. 4 mm

● Fins Height: Min 0.25” (6.35 mm) To Max.1.5” (38 mm)

● Fin Density: Min 43 Fins per Meter to Max. 287 Fins per Meter

● Material: Carbon Steel, Stainless Steel, Alloy Steel, Carton steel, Duplex Steel.

Post time: Jun-17-2022