Cangzhou Datang Steel Pipe Co., Ltd. is one of China’s most reputable manufacturers and suppliers of hot-dip galvanized finned tubes. We welcome you to purchase high-quality hot-dip galvanized cold-rolled finned tubes from our factory. We offer excellent service and reasonable prices.

What are hot-dip galvanized finned tubes?

Hot-dip galvanized finned tubes are enhanced heat transfer elements with fins welded to the outer surface of a base tube and then treated with hot-dip galvanizing for corrosion protection. They are widely used in high-temperature, high-humidity, or mildly corrosive environments such as industrial waste heat recovery, district heating, and nuclear power auxiliary systems. Their core advantage lies in balancing high-efficiency heat exchange with corrosion resistance, making them particularly suitable for long-term stable operation in complex conditions such as humidity, dust, and outdoor environments.

I. Structure and Working Principle

Hot-dip galvanized finned tubes consist of three parts: a base tube (usually a seamless carbon steel tube), fins (mostly steel or aluminum strips), and an outer galvanized layer.

Fin Structure: The fins are fixed to the base tube through high-frequency welding, winding, or rolling processes, increasing the heat exchange area by 3–8 times compared to ordinary bare tubes, significantly improving heat transfer efficiency.

Hot-dip Galvanized Layer: The formed finned tube is immersed in molten zinc at 440–460℃, forming a 50–150μm thick zinc-iron alloy layer. This layer provides a “sacrificial anode” protection mechanism, preventing corrosion of the substrate even in the event of localized damage.

II. Main Advantages

1.Strong Corrosion Resistance: The zinc layer acts as a sacrificial anode, preferentially oxidizing the steel and effectively protecting the internal steel. This makes it particularly suitable for high-humidity and high-corrosion environments such as greenhouses, coastal areas, and chemical plants.

2.High heat dissipation efficiency: The fins significantly increase the surface area, improving the air-side convective heat transfer coefficient by 35%–50%, achieving rapid heating and uniform temperature distribution.

3.Long service life: In C3-level corrosive environments, hot-dip galvanized finned tubes can last 15–20 years, more than three times that of ordinary carbon steel tubes.

4.Outstanding economic efficiency: Compared to stainless steel heat exchange tubes, costs are reduced by 40%–60%, maintenance costs are reduced by more than 80% annually, and the total life-cycle cost is lower.

III. Production Process

Base Tube Preparation: Low-carbon steel tubes such as Q235B are selected and subjected to cutting, rust removal, and straightening.

Fin Forming: After longitudinal shearing and leveling, the steel strip is bonded to the base tube through high-frequency welding or winding.

Welding Reinforcement: A combination of argon arc welding and manual electric arc welding is used to connect the flanges, ensuring a tight seal.

Hot-Dip Galvanizing: The entire flange is immersed in molten zinc at high temperature, forming a dense protective layer that covers all metal surfaces, including seams.

Quality Inspection: Hydrostatic testing, penetrant testing, and coating thickness testing are conducted to ensure product reliability.

IV. Common Application Scenarios

Industrial Sector: Used for boiler waste heat recovery, metallurgical cooling, petrochemical reactor heat dissipation, and other high-temperature and high-pressure applications.

Agricultural Greenhouses: Used for heating mushroom, vegetable, and flower greenhouses, solving the problem of ordinary radiators easily rusting due to high humidity.

Civil Buildings: Heating systems for workshops, factories, and farms, supporting flange connections for flexible installation.

Energy & Power: Key equipment such as generator cooling systems and air preheaters.

Datang Quality Control for Hot Dip Galvanised Finned Tube

The quality of the hot dip galvanised fin tube is assured by hydrostatic or pneumatic testing, eddy current testing and tensile testing to verify the mechanical bond between the inner tube and the outer fins.

Datang Delivery condition:

Tube ends are square cut, free burrs, internally dried and air blown clean, externally coated with Anti-rust at both ends of hot dip galvanised fin tube.