ASME SA179 KL Type Aluminum Finned Tube for Economizer and Heat Recovery

KL Type Wound Finned Tube – ASTM A179 Carbon Steel Base Tube with Aluminum Fins

Product Introduction

KL Type Wound Finned Tubes (also known as Knurled L-Foot Tension Wound Finned Tubes) are high-efficiency heat transfer components designed for air-cooled heat exchangers, economizers, and industrial cooling systems.

This product features a seamless cold-drawn ASTM A179 / ASME SA179 carbon steel base tube combined with high-purity aluminum (AL1060 / AL1100) fins. The unique knurled L-foot tension-winding process creates a strong mechanical interlock between the fin foot and the base tube surface, delivering superior heat transfer performance, improved vibration resistance, and reliable operation up to 250–260°C.

Finned Tube Structure – ASTM A179 Base Tube + Aluminum Fins

1. Base Tube Material: ASTM A179 / ASME SA179 Carbon Steel

Seamless cold-drawn low-carbon steel tube manufactured to ASTM A179 / ASME SA179 standards. The outer surface is precisely knurled before finning to enhance mechanical bonding.

2. Fin Material: Aluminum (AL1060 / AL1100)
High-purity aluminum strip is formed into an L-shape and tension-wound onto the knurled base tube. After winding, the L-foot is further knurled into the tube surface, locking the fin securely in place.

3. Embedding / Manufacturing Process

• Base tube outer surface is knurled
• Aluminum strip is continuously formed into L-profile and tightly wound under controlled tension
• Fin foot is simultaneously knurled into the tube surface
• Both ends of the tube are left bare (unfinned) for welding or tube-sheet insertion
• Tubes are cleaned, dried, and anti-rust protected at ends

This process increases metal-to-metal contact area by approximately 30–50% compared with standard L-type fins, resulting in lower thermal resistance and better long-term performance under thermal cycling.

Chemical Composition – ASTM A179 Base Tube Material

Mechanical Properties of ASTM A179 Base Tube

Chemical Composition – Aluminum Fin Material (AL1060)

Dimensional Range & Tolerance – ASTM A179 + Aluminum KL Finned Tube

Performance Advantages

• Excellent heat transfer efficiency due to increased contact area from knurled L-foot design
• Maximum continuous operating temperature: 250–260°C
• Maximum working pressure: up to 3.2 MPa
• Good atmospheric corrosion resistance (fin foot protects base tube)
• High resistance to vibration and thermal cycling
• Lightweight aluminum fins reduce overall equipment weight
• Cost-effective alternative to extruded or G-type finned tubes for medium-temperature applications
• Fully mechanical bonding – no welding or brazing required

Application Fields

KL Type ASTM A179 + Aluminum Finned Tubes are widely used in:

• Air-cooled heat exchangers (ACHE) in petrochemical and oil & gas plants
• Economizers and air heaters in power generation and waste-heat recovery systems
• Compressor coolers and gas coolers
• HVAC and industrial dry coolers
• Refrigeration and air-conditioning systems
• Chemical and fertilizer plant process coolers
• Incineration and flue-gas heat recovery units

Our Advantages & Experience

As a specialized manufacturer and exporter of finned tubes, we offer:

• Full production capability for L, LL, KL, G, and extruded finned tubes
• Strict quality control according to ASTM, ASME, and customer specifications
• Mill Test Certificates (EN 10204 3.1 / 3.2) provided with every shipment
• Custom sizes, bare ends, and packaging available
• Extensive export experience to Europe, Middle East, Southeast Asia, and South America
• Competitive pricing with reliable lead times and professional technical support