ASTM A312 High Frequency Welded Helical Finned Tube
ASTM A312 high-frequency welded spiral finned tubes are made of stainless steel and are high-performance finned tubes suitable for corrosive or high-temperature environments. They are commonly used in demanding applications such as power generation, petrochemicals, and waste heat recovery.
- Base Tube Material:
CS (A106, A333, A179, A210, P5, P11, P22)
SS (SS304, SS316, Duplex SS2205, Super Duplex SS32750)
Nickel Alloys (825, Inconel Alloy 625, High chrome high nickle incoloy alloy Monel 400) - Tube OD:15.88mm~273mm or customized
Product Details
ASTM A312 stainless steel high-frequency welded finned tubes are high-efficiency heat exchange elements that metallurgically combine stainless steel fins with a stainless steel base tube using high-frequency induction welding. Their core advantages lie in excellent corrosion resistance, extremely high weld strength, and extremely low contact thermal resistance. They are widely used in corrosive environments such as chemical, food, and marine settings, as well as in civil heating and industrial waste heat recovery.
What Is ASTM A312?
- TP304 / TP304L
- TP316 / TP316L
- TP321
- TP347
What Is a High Frequency Welded (HFW) Helical Finned Tube?
- Full contact along the fin root
- High thermal conductivity
- Excellent mechanical strength
- Consistent, high-speed production
- Fin height: 10–30 mm
- Fin thickness: 1.0–3.0 mm
- Fin pitch: 3–12 mm (customizable)
Can You Combine ASTM A312 with HFW Helical Fins?
- Superior corrosion resistance (from ASTM A312-grade stainless steel)
- Efficient heat transfer (from the helical fin design)
- Long service life in harsh environments (e.g., sulfuric acid plants, offshore platforms, biomass boilers)
“Helical finned tube with base pipe conforming to ASTM A312 TP316L, fin strip in matching material, high-frequency welded per manufacturer’s quality standards.”
Do not claim the entire finned tube assembly meets ASTM A312—that standard only governs the base pipe dimensions, chemistry, and mechanical properties.
Process Principles and Technical Characteristics
High-Frequency Welding Process: This process utilizes the skin effect and proximity effect of a 200-500kHz high-frequency current to instantly heat the metal at the contact surface between the stainless steel fins and the base tube to a plastic state (approximately 1000-1200℃). Mechanical pressure is then applied to achieve molecular-level diffusion metallurgical bonding, achieving a weld success rate of over 95%. This solid-state welding requires no solder, has a small heat-affected zone, and produces clean and stable welds.
Core Performance Advantages:
Superior Corrosion Resistance: Made of 304 or 316L stainless steel, it effectively resists corrosive media such as acids, alkalis, and salt spray. In chemical and marine environments, its service life can reach 10-15 years, far exceeding that of carbon steel.
Extremely low contact thermal resistance and high heat transfer efficiency: Metallurgical bonding results in extremely low thermal resistance between the fins and the base tube (down to below 0.0005 m²·K/W), enabling rapid heat transfer. The fins significantly increase the heat transfer area, making the total heat dissipation area 5-12 times that of a bare tube, and improving heat transfer efficiency by 4-7 times compared to ordinary pipes.
Excellent structural stability and long lifespan: High welding strength (peel strength ≥15MPa), capable of withstanding severe temperature cycling (-40℃ to above 400℃) and vibration, with a fin shedding rate of less than 0.1% and a structural lifespan of 15-20 years.
Anti-dust accumulation and easy maintenance: Smooth surface, corrosion-resistant and wear-resistant, with strong anti-dust accumulation capability; routine maintenance mainly requires periodically blowing dust off the fin surface with compressed air.
Why Choose Stainless Steel Finned Tubes?
| Benefit | Description |
|---|---|
| Corrosion Resistance | Withstands acidic, alkaline, and saline environments |
| High-Temperature Stability | Performs reliably up to 800°C (depending on grade) |
| Low Maintenance | Resists fouling and degradation over time |
| Long Service Life | Reduces downtime and replacement costs |
Need a reliable supplier of stainless steel helical finned tubes?
We manufacture high-frequency welded finned tubes using ASTM A312, ASTM A213, and other base standards—with full traceability, testing, and global delivery. [Contact us today] for a quote or technical consultation.
RFQ
1.SS ASTM A312 GR TP347H High Frequency Welded Helical Finned Tube —— February 8, 2026
PIPE, SPECIAL PURPOSE:
MATERIAL SS ASTM A312 GR TP347H, SIZE OD 114.3 X LG
4474 X THK 7.14 MM / 4 IN, ENDS BEVEL,
FFT:WITH FINNED,
MILL TEST CERTIFICATE
QTY 12
- Datasheet
- Drawing
- Certificates
| Parameter | Specification |
|---|---|
| Base Tube Material | CS (A106, A333, A179, A210, P5, P11, P22), SS (SS304, SS316, Duplex SS2205, Super Duplex SS32750), Nickel Alloys (825, Inconel Alloy 625, High chrome high nickel incoloy alloy Monel 400) |
| Tube OD | 15.88 mm ~ 273 mm or customized |
| Tube Wall Thick | 2 mm ~ 28.6 mm |
| Length | 1 Meters to 28 Meters (92 feet) |
| Fin Material | CS (08F, SPCC), SS (SS304, SS316, 409, 410, 321, 347) |
| Fin Height | 8 mm ~ 35 mm |
| Fin Thick | 1 mm ~ 1.5 mm |
| Fin Pitch | 3 ~ 333 FPM (1 FPI ~ 7 FPI) |
| Fin Type | Solid, U Type, S Type, Serrated |
| Finned tube welding rate | more than 98% |
| Tube Ends | Plain cut or beveled at any degree |
ASTM A312 High Frequency Welded Helical Finned Tube Appearance Dimension Inspection
High frequency welded stainless steel finned tube appearance dimension inspection is one of the important links to ensure the quality and performance of fin tubes.
The inspection items mainly include fin height, fin spacing, fin thickness, base tube wall thickness and outer diameter, etc.
High Frequency Welded Stainless Steel Finned Tube Bending Processing
Bending of fin tubes is an important step in the production process of high frequency welded stainless steel finned tubes. Bending is to bend the finned tube material through specific mechanical equipment to form a suitable curvature to meet different usage requirements.
This step requires strict control of the bending angle and curvature to ensure the fit between the fin and the base tube and the heat dissipation effect.
High-frequency Welded Helical Stainless Steel Finned Tube Application
- Waste Heat Recovery Units (WHRUs)
- Air Coolers & Gas-Gas Heat Exchangers
- Fired Heaters & Superheaters
- Chemical Processing Plants
- Marine Exhaust Economizers
- Flue Gas Desulfurization (FGD) Systems
- Their ability to resist scaling, pitting, and chloride stress corrosion cracking makes them indispensable where reliability matters.
How to Specify Your Finned Tube Correctly
- Base tube standard: e.g., ASTM A312 TP304, OD × WT (e.g., 1.5″ × 2.0 mm)
- Fin material: Same as base or dissimilar (e.g., Incoloy 800 for high-temp zones)
- Fin dimensions: Height, thickness, pitch
- Welding method: High-frequency resistance welding (HFRW)
- Testing requirements: Eddy current, pull-off strength (>200 N/cm typical), visual inspection
