1. The heat transfer characteristics of G-type finned tubes are related to the contact thermal resistance between finned tubes, and the core of the contact thermal resistance is the contact pressure between them. 

Obviously, the heat transfer characteristics of welded chips and bushings are better, followed by bimetal pipes, and the insertion and winding are poor. After re-flanging,

 the contact area of the KLM finned tube is increased by about 50% without interference from the outside diameter tolerance of the tube. After many cold cycles, the contact is good,

 the contact thermal resistance is small, and the heat transfer characteristics are high. The slotted finned tube can increase the airflow disturbance and increase the total heat transfer coefficient by about 20%.

2. With the increase of the wall temperature of the room temperature performance G-fin tube, the contact pressure between the pin and the tube changes, and the contact thermal resistance also changes.

 The fluctuation value depends on the type of finned tube and the initial contact pressure. As the temperature increases,

 the pin tension around the chip decreases rapidly, so the contact thermal resistance increases rapidly. Bimetal rolling can be stable over a wide temperature range.

3. The bottom tube of G type fin tube is protected by the wing to prevent atmospheric corrosion. Due to the different range of protection, the ability of various types of finned tubes to resist atmospheric corrosion is also different.

 In a variety of finned tubes, bimetallic rolling is good. All finned tubes treated with hot dip galvanization have good atmospheric corrosion resistance.

 Chemical plants with corrosive gases in the atmosphere should pay special attention to the choice of raw materials and types of finned tubes, and aluminum needles are easy to corrode.

4. In many finned tube operations, the pressure is the material and wall thickness chosen in the bottom tube, but it is also related to the type of finned tube. Rolled (bottom tube for aluminum copper material) low pressure resistance, not suitable for use in air coolers.

 The bottom tube of the embedded chip has a rolling groove, and the working pressure decreases with the increase of the working temperature.

5. Clean the dirt on the gas side of the dirty G-fin tube, usually using compressed air, steam or high-pressure water. In this way, the fins have a corresponding stiffness.

6. Manufacturing cost. From the raw material consumption of G-finned tubes, the circumference is low, and the bimetal rolls and sleeves are high. Bimetallic aluminum rolling consumes 1/3 ~ 1/2 more than sheet. 

From the perspective of production and manufacturing processing costs, the perimeter is lower, the bimetal rolling is higher, and the sleeve is higher. All finned tubes that require surface hot-dip galvanizing are more expensive in terms of raw material consumption or manufacturing process.