Gost 550-2020 Steel 20 Embedded Finned Tube with Al1060 Fins For Air Coolers

Gost 550-2020 Steel 20 Embedded Finned Tube with Al1060 Fins For Air Coolers

1. Product Definition & Structure

The GOST 550-2020 Steel 20 Embedded Finned Tube with AL1060 Fins is a mechanically bonded finned tube used for gas-to-liquid or gas-to-gas heat exchange, where the outside medium is air or flue gas and the inside medium is a process fluid.

Structure:

Base tube: GOST 550-2020 compliant, Steel 20 carbon steel seamless tube

Fins: AL1060 commercially pure aluminum strip

Bonding method: Embedded (G-Fin), mechanical lock without welding or metallurgical bonding

2. Applicable Standards & Material Specifications

2.1 Base Tube Standard: GOST 550-2020

This Russian standard specifies seamless steel tubes for petroleum refining and petrochemical industries, covering chemical composition, mechanical properties, NDT, and dimensional tolerances.

2.2 Base Tube Material: Steel 20 Chemical Composition

2.3 Steel 20 Mechanical Properties at Room Temperature (Minimum / Typical)

Based on minimum requirements of GOST 550-2020 for seamless Steel 20 tubes.

2.4 Fin Material: AL1060

3. Performance Characteristics (ParameterBased)

3.1 Heat Transfer

Medium-to-high efficiency among mechanical finned tubes, between L-type and HF-welded.

In typical air cooler duty, air-side thermal resistance accounts for 60% – 80% of total.

Aluminum’s high conductivity (234 W/(m·K)) is partially offset by steelaluminum contact resistance.

3.2 Mechanical Stability

Higher pull-out resistance than L-type fins.

Contact pressure may relax under daily start-stop cycles, but remains acceptable for most industrial air coolers.

3.3 Corrosion Behavior

Aluminum forms a protective oxide layer in normal air, but degrades in moist, sulfur-containing flue gas.

Steel 20 requires internal corrosion control depending on the tubeside medium.

4. Typical Applications (Industry-Focused)

4.1 Petrochemical Air Coolers

Overhead condensers, compressor interstage coolers

Tube side: hydrocarbons, steam, light oil

Shell side: ambient air (-30°C to +45°C)

4.2 Waste Heat Recovery

Gas turbine exhaust, furnace flue gas (inlet ≤ 320°C)

Caution required if sulfur > 500 ppm or moisture > 15% (acid dew point)

4.3 Natural Gas Compressor Stations

Interstage cooling of compressed natural gas

Lightweight aluminum fins with good airside performance

5. Technical Comparison with Other Fin Types (No Marketing Exaggeration)