ASTM A312 TP304H Solid Finned Tube with SS304 Fins For Air Heaters and Economizers

ASTM A312 TP304H Solid Finned Tube with SS304 Fins For Air Heaters and Economizers

An ASTM A312 TP304H HFW Solid Finned Tube with SS304 Fins is a high-frequency welded stainless steel tube, made from a high-temperature grade of 304 stainless, with individual strips of standard 304 stainless steel welded to its outside to form fins. It is an engineered component optimized for durable, efficient heat transfer in demanding industrial applications.

1. Base Tube: ASTM A312 TP304H seamless pipe

(1). Chemical Composition (Weight %)

Key Points:

Carbon range 0.04–0.10% is the main difference from standard TP304 (C max 0.08%).

The "H" grade requires a minimum Carbon of 0.04% and often restricts the C range more tightly to ensure high-temperature performance.

Chromium and Nickel provide oxidation resistance and austenitic structure stability.

(2). Mechanical Properties (Room Temperature)

Note: Properties are for the tube material in the final heat-treated condition.

2. Fins: SS304 HFW Solid fins

• HFW tubes are more cost-effective than seamless tubes for many applications and are perfectly suitable for the pressures and temperatures TP304H is rated for. The weld seam is often heat-treated to normalize its properties.
  • This describes the fin type. "Solid fins" mean the fins are discrete, individual strips (usually rectangular or trapezoidal in cross-section) that are attached to the tube.
  • This is in contrast to "integral fins" (which are extruded or rolled from the tube wall itself) or "serrated fins" (where the fin strip has cuts to enhance turbulence).
• SS304 is the same base alloy as the tube (TP304H), but without the "H" certification. This is standard practice. The fins, being thinner, typically do not require the same high-temperature strength certification as the pressure-bearing tube. Using the same family of alloy ensures compatible thermal expansion and good weldability.

3. Key Characteristics & Typical Applications of ASTM A312 TP304H HFW Solid Finned Tube with SS304 Fins

• Enhanced Heat Transfer: The fins multiply the external surface area, making heat exchange with air or gas much more efficient.
• High-Temperature Capability: The "H" grade tube is designed for sustained operation at temperatures where creep is a design factor.
• Corrosion Resistance: The 304 stainless steel provides good resistance to oxidation and many corrosive environments.
• Pressure Integrity: The tube meets ASTM A312 standards for wall thickness and strength, allowing it to contain internal fluid pressure.

Primary Application Areas

1. Power Generation

2. Petrochemical & Refining

3. Industrial Boilers & Furnaces

4. Waste-to-Energy & Incineration