ASTM A106 Embedded G Type Fin Tube With Cu-T2 Fin Used For Comdemser amd Air Preheaters

ASTM A106 Embedded G-Type Fin Tube Basic Description
It is a grooved embedded fin tube, where the "G-type" refers to the grooved structure on the base tube. The base tube complies with the ASTM A106 standard, which is a seamless carbon steel tube designed for high-temperature service, with a size range of 1/8 inch to 48 inches (DN6 to DN1200). The Cu-T2 fin is a pure copper fin with high thermal conductivity and good ductility. The fin is embedded in the spiral groove on the outer surface of the ASTM A106 base tube and fixed by backfilling the metal extruded from the groove, forming a tight integrated structure for efficient heat transfer. Its common specifications include a base tube outer diameter of 16 - 63mm, fin pitch of 2.1 - 5mm, and fin thickness of about 0.4mm.

ASTM A106 Embedded G-Type Fin Tube Strength

• Base Tube Strength: ASTM A106 carbon steel tubes (especially the common Grade B) have excellent mechanical properties. They typically have a tensile strength suitable for high-temperature working conditions, along with good yield strength and toughness. This allows the base tube to withstand the pressure and thermal stress of industrial heat exchange systems.
• Fin - Base Tube Bond Strength: The embedded G-type structure enables the Cu-T2 fin to be firmly locked in the groove of the base tube. Unlike simple winding fins, the backfilled metal from the groove enhances the connection tightness between the fin and the tube. This structure not only reduces heat resistance at the interface but also gives the fin strong anti - vibration and anti - shedding capabilities, making the tube suitable for working environments with slight vibrations, such as power plant boilers.
• Temperature Adaptability: It can operate stably at 350 - 400℃. The Cu-T2 fin can resist thermal deformation within this temperature range, and the ASTM A106 base tube maintains structural stability without softening or cracking, ensuring the overall strength of the fin tube during long-term high-temperature operation.

ASTM A106 Embedded G-Type Fin Tube Making Process

1. Base Tube Preparation: Select ASTM A106 seamless carbon steel tubes that meet the specifications. Perform processes such as cutting, derusting, and degreasing according to the required length. Conduct flaw detection and dimensional inspection to ensure the base tube has no defects like cracks or uneven wall thickness.
2. Groove Machining: Use special equipment to process spiral grooves with a depth of about 0.25 - 0.5mm on the outer surface of the treated ASTM A106 base tube. The groove spacing and depth are determined based on the fin specifications.
3. Fin Forming and Embedding: Cut Cu-T2 into thin strips of the required width and thickness. Then, twist the Cu-T2 fin strips and embed them into the spiral grooves of the base tube through a specialized embedding machine.
4. Backfilling and Fixing: While embedding the fins, use rolling tools to extrude the metal on the edge of the base tube's grooves. The extruded metal backfills the gap at the root of the Cu-T2 fins, firmly locking the fins in the grooves to form an integrated structure.
5. Post - Processing: Carry out surface treatment such as anti-corrosion coating on the finished fin tube to prevent electrochemical corrosion between the carbon steel base tube and the copper fin. Finally, conduct tests such as thermal performance detection and pressure resistance tests to ensure product quality.

ASTM A106 Embedded G-Type Fin Tube Advantages

• Outstanding Heat Transfer Efficiency: Cu-T2 pure copper has extremely high thermal conductivity, which is far superior to carbon steel and aluminum. Combined with the G-type embedded structure that minimizes interface heat resistance, the fin tube can quickly transfer the heat of the medium in the base tube to the external environment, and its heat transfer efficiency is much higher than that of bare tubes and ordinary welded fin tubes.
• Strong Structural Stability: The embedded and backfilled connection method avoids the problem of fin shedding that is prone to occur in welded or bonded fins. The structure is stable and reliable, and it can adapt to harsh working conditions such as vibration and frequent temperature changes.
• Good Processability: The ASTM A106 base tube is easy to cut, bend and weld, and can be processed into U-shaped or other special-shaped structures according to the design requirements of heat exchangers. The Cu-T2 fin has good ductility and is not easy to break during the embedding process.
• Cost - Effective Performance: Compared with fin tubes made entirely of copper, using the ASTM A106 carbon steel base tube with Cu-T2 fins reduces the overall cost while retaining high heat transfer performance, achieving a balance between performance and cost.

ASTM A106 Embedded G-Type Fin Tube Application
This fin tube is widely used in industrial heat exchange scenarios that require high heat transfer efficiency and resistance to medium - high temperature. Typical applications include:

• Petrochemical and Refining Industry: It is used in heat exchangers, condensers and waste heat recovery devices in oil refineries and chemical plants to handle heat exchange tasks of oil, natural gas and chemical media.
• Power Industry: Applied to economizers, air preheaters and waste heat boilers in thermal power plants and renewable energy power plants, it helps improve the utilization rate of thermal energy and reduce energy consumption.
• Refrigeration and Air - Conditioning Field: Used in the condenser and evaporator of large central air - conditioning systems and industrial refrigeration equipment. The high thermal conductivity of Cu-T2 fins can improve the refrigeration efficiency.
• Other Fields: It is also used in heat exchange equipment in metallurgy, cement and pharmaceutical industries, such as waste heat recovery from metallurgical furnace flue gas and heat sterilization systems in pharmaceutical factories.

ASTM A106 Embedded G-Type Fin Tube FAQ

Q1: Why does electrochemical corrosion easily occur? How to deal with it?
A: The ASTM A106 carbon steel base tube and Cu-T2 copper fin are different metals. In a humid or corrosive environment, a galvanic cell is formed, leading to electrochemical corrosion. The solution is to apply an anti-corrosion coating on the surface of the fin tube, or install an insulating gasket at the connection between the fin and the tube to isolate the two metals. Regular inspection and timely replacement of corroded parts are also necessary.
 

Q2: What causes the decrease in heat transfer efficiency during use?
A: The main reasons are the accumulation of dust and dirt on the Cu-T2 fins and the scaling inside the base tube. Dust and dirt form an insulating layer on the fin surface, while scaling blocks the heat transfer inside the tube. It is recommended to install a filter at the air inlet, and regularly use high-pressure water washing or chemical cleaning agents to clean the fins and the inner wall of the tube.
 

Q3: Can it be used in high-pressure working conditions?
A: No. The G-type embedded process will cause stress concentration on the wall of the ASTM A106 base tube. The fin tube is not suitable for medium and high-pressure systems. It is mainly used in low to medium-pressure heat exchange scenarios. For high-pressure conditions, it is necessary to choose special extruded or welded fin tubes.