Double H-Type Finned Tubes for Waste Heat Recovery Boilers – ASTM A179 Carbon Steel
Product Overview
Double H-Type Finned Tubes are high-efficiency heat transfer components specifically designed for waste heat recovery boilers, industrial economizers, and energy-saving heat exchanger systems. Manufactured with ASTM A179 seamless carbon steel tubes, these finned tubes provide excellent thermal performance, mechanical reliability, and long service life in applications where recovering heat from exhaust gases is critical.
The unique double H-fin structure consists of two symmetrical rectangular fins welded onto the opposite sides of the base tube, forming an optimized gas flow channel. Compared with conventional plain tubes or standard spiral fin tubes, Double H-type finned tubes significantly increase the external heat transfer area while reducing ash accumulation and improving resistance to gas-side fouling.
ASTM A179 material offers excellent thermal conductivity, good weldability, and stable mechanical performance, making these tubes widely used in coal-fired boilers, gas-fired boilers, biomass boilers, waste incineration plants, power generation systems, and industrial waste heat recovery units.
Key Features of Double H-Type Finned Tubes
1. High Heat Transfer Efficiency
The double H-fin design expands the heat exchange surface area and enhances turbulence in the flue gas flow, improving overall boiler efficiency and reducing fuel consumption.
2. Excellent Anti-Fouling Performance
The open gas passage between H-shaped fins minimizes dust accumulation and allows easier cleaning compared with tightly packed fin structures, making them suitable for dirty exhaust gas environments.
3. Strong Mechanical Strength
The fins are securely welded to the ASTM A179 tube surface, providing high structural stability under thermal cycling, vibration, and long-term operation.
4. Optimized for Waste Heat Recovery Systems
Double H-type finned tubes are commonly installed in:
- Waste heat recovery boilers (WHRB)
- Boiler economizers
- Gas-to-water heat exchangers
- Industrial exhaust heat recovery systems
- Power plant heat recovery equipment
- Cement plant and steel plant waste heat systems
Technical Specifications
Base Tube Material
ASTM A179 / ASME SA179
Low carbon seamless steel tube designed for heat exchanger and condenser applications.
Typical Applications:
- Economizer tube banks
- Waste heat recovery boilers
- Feedwater preheaters
- Industrial heat exchangers
Standard Size Range
The dimensions of Double H-type finned tubes can be customized according to boiler design requirements.
Common Base Tube Sizes
| Parameter |
Standard Range |
| Outside Diameter (OD) |
25.4 mm – 63.5 mm |
| Wall Thickness |
2.0 mm – 6.0 mm |
| Tube Length |
3000 mm – 12000 mm |
| Fin Height |
10 mm – 30 mm |
| Fin Thickness |
1.0 mm – 2.5 mm |
| Fin Pitch |
8 mm – 20 mm |
| Fin Width |
20 mm – 50 mm |
Typical Manufacturing Sizes
- 31.8 * 2.0 mm
- 38.1 * 2.5 mm
- 44.5 * 3.0 mm
- 50.8 * 3.5 mm
- 57.2 * 4.0 mm
(Custom dimensions available according to customer drawings and heat transfer requirements.)
Manufacturing Process
The production process of Double H-type finned tubes includes:
- ASTM A179 seamless tube inspection
- Tube surface cleaning and preparation
- Precision cutting of H-shaped fins
- Automatic resistance welding or high-quality fin welding
- Dimensional inspection
- Surface treatment and final quality verification
The welding process ensures strong bonding between fins and tubes while maintaining excellent thermal conductivity.
Chemical Composition of ASTM A179 Material
| Element |
Maximum Content (%) |
| Carbon (C) |
0.06 – 0.18 |
| Manganese (Mn) |
0.27 – 0.63 |
| Phosphorus (P) |
≤ 0.035 |
| Sulfur (S) |
≤ 0.035 |
ASTM A179 is a low-carbon steel grade optimized for heat exchanger applications, providing good forming ability and corrosion resistance in normal boiler operating conditions.
Mechanical Properties of ASTM A179
| Property |
Requirement |
| Tensile Strength |
≥ 325 MPa |
| Yield Strength |
≥ 180 MPa |
| Elongation |
≥ 35% |
| Hardness |
Max. 72 HRB |
These mechanical properties provide sufficient strength for continuous operation under thermal expansion, pressure variation, and repeated heating cycles.
Inspection and Testing Methods
To ensure reliability and compliance with international heat exchanger standards, Double H-type finned tubes undergo comprehensive quality inspections.
1. Raw Material Inspection
- Material certificate verification (MTC)
- Chemical composition analysis
- Mechanical property testing
2. Tube Inspection
- Outside diameter measurement
- Wall thickness measurement
- Straightness inspection
- Surface defect examination
3. Welding Quality Inspection
- Fin-to-tube weld appearance inspection
- Welding strength verification
- Dimensional accuracy inspection
4. Non-Destructive Testing (NDT)
Available testing methods include:
- Eddy current testing
- Ultrasonic testing
- Magnetic particle testing (when applicable)
- Liquid penetrant testing (when required)
5. Hydraulic Pressure Test
ASTM A179 tubes are hydraulically tested to verify pressure resistance and leak tightness.
6. Final Inspection
Final inspection includes:
- Fin spacing measurement
- Tube length verification
- Surface quality inspection
- Packing inspection
Inspection documents can be supplied according to customer requirements, including:
- EN 10204 3.1 Material Certificate
- Inspection reports
- Test records
- Dimensional reports
Advantages Compared with Traditional Finned Tubes
| Feature |
Double H-Type Finned Tube |
Conventional Spiral Fin Tube |
| Heat Transfer Area |
High |
Medium |
| Dust Resistance |
Excellent |
Moderate |
| Gas Flow Resistance |
Lower |
Higher |
| Cleaning Performance |
Easy |
More difficult |
| Suitable for Waste Gas |
Excellent |
Limited |
Typical Applications
Double H-type finned tubes manufactured from ASTM A179 are widely used in:
Waste Heat Recovery Boilers
Recovering energy from high-temperature exhaust gases to produce steam or heat process water.
Industrial Economizers
Improving boiler efficiency by preheating feedwater before entering the boiler.
Power Generation Systems
Increasing energy recovery efficiency in thermal power plants.
Manufacturing Industries
Applied in:
- Steel plants
- Cement factories
- Chemical plants
- Petrochemical facilities
- Waste-to-energy plants
Why Choose Our ASTM A179 Double H-Type Finned Tubes?
- Manufactured according to ASTM A179 / ASME SA179 standards
- Optimized design for waste heat recovery applications
- High fin-to-tube welding quality
- Excellent resistance to fouling and dust accumulation
- Customized dimensions available
- Complete inspection documentation provided
- Suitable for long-term industrial operation
Our Double H-type finned tubes provide a reliable solution for improving boiler efficiency and maximizing energy recovery from industrial waste heat sources.
Your message must be between 20-3,000 characters!
