Crimped Fin Tubes

Crimped fin tubes (often referred to as spiral crimped or corrugated finned tubes) are extended surface tubes manufactured by helically wrapping a continuous metal strip around a base tube. During the winding process, the inner edge of the fin strip is mechanically crimped or rippled, allowing the flat metal strip to form around the rounded tube without tearing or buckling.

Production Process of Crimped Fin Tubes

1. Base Tube Preparation: Straighten and rust-remove the base tube first to ensure a smooth surface finish.

2. Fin Forming: Press the metal strip (commonly carbon steel or aluminum) into an L-shaped or U-shaped cross-section.

3. Spiral Winding & Crimping: Wrap the fin spirally around the base tube using a fin-winding machine. A pressure roller applies a radial pressure of 15–25 MPa to tightly press the fin against the tube, eliminating any air gaps.

4. Finishing & Surface Treatment: Trim, shape, and perform final surface treatment on the completed tube.

Optional Step: Some products undergo hot-dip galvanizing, where the assembly is immersed in molten zinc at 440–460°C to form a protective anti-corrosion layer, reaching a coating thickness of 80–120 μm.

Cost-Effectiveness & Practical Applications

Spiral crimped fin tubes are a highly cost-effective choice primarily designed for low-to-medium temperature and low-pressure conditions.

1. Operating Conditions

• Operating Temperature: Generally -30 C° to 150 C°

• Operating Pressure: Max 1.0 MPa

2. Key Applications

• Retrofitting heating systems in older residential communities

• Climate control in agricultural greenhouses

• Basement and underground space heating

• Humid environments in food processing workshops

• Localized space heating in light industrial plants

Economic & Performance Advantage

In a 80C° hot-water heating scenario, the heat dissipation rate reaches 500 — 800 W/m.

While its thermal output is slightly lower (10 % – 15 %) than high-frequency welded (HFW) fin tubes, the manufacturing cost is 25 % – 40% lower, making it significantly more economical for large-scale setups.

Surface Treatment Selection Guide

• Hot-Dip Galvanized: Best suited for humid or mildly corrosive environments where long-term durability is critical.

• Electro-Galvanized: Ideal for dry environments where visual appeal and a clean finish are prioritized.

Continuous Spiral Crimped Fin Tube Material Options & Combinations

Because the base tube and fins are mechanically bonded, different materials can be paired to optimize thermal efficiency, corrosion resistance, and total cost:

• Base Tube Materials:

  • Carbon Steel: 20#, Q235, ASTM A179 / A214,Others Service:Hot Dip Galvanzied

  • Нержавеющая сталь: SS304 / 304L, SS316 / 316L

  • Медь & Copper Alloys: C12200, TP2

• Fin Strip Materials:

  • Aluminum: 1060, 1100, 3003

  • Carbon Steel: SPCC, Q195

  • Медь: C1100

  • Нержавеющая сталь: SS304