ASTM A312 TP321H HFW Solid Finned Tube with 11-13Cr Fins For Process Furnaces

ASTM A312 TP321H HFW Solid Finned Tube with 11-13Cr Fins For Process Furnaces

ASTM A312 TP321H HFW Solid Finned Tube with 11-13Cr Fins is a high-performance, composite tube designed for efficient heat transfer in high-temperature and corrosive environments. It consists of a core pipe made of a special stainless steel (TP321H) with fins made of a heat-resistant chromium steel (11-13% Cr) welded onto its outer surface. The "HFW" and "Solid" describe the manufacturing process of the fins.

Here are some detailed Component Breakdowns:

1. Bare Tubes: ASTM A312 TP321H seamless tubes

(1)Chemical Composition (Weight %)

The composition is specified in ASTM A312/A312M standard. The following table shows the requirements for TP321H.

Key Point on Stabilization: The minimum Titanium content is calculated as 5 times the sum of the Carbon + Nitrogen content. This ensures there is enough Titanium to fully stabilize the steel and prevent chromium carbide formation at grain boundaries.

(2). Mechanical Properties

The mechanical properties are specified for the material in the annealed condition.

2. HFW Finned Tube Type-Solid Finned Tube

• Solid Fins: This means the fins are made from a solid strip of metal and are integrally bonded to the base tube (in this case, via HFW). They are not a separate piece mechanically attached (like embedded or L-foot fins).
• Key Advantage: The solid, welded bond has very low thermal resistance, allowing for highly efficient heat transfer from the tube to the fins and into the surrounding medium (or vice-versa). It also makes the assembly robust and resistant to fin loosening due to thermal cycling.

3. Fins Material: 11-13Cr

11-13% Chromium (Cr) Steel: This is a classification for a family of heat-resistant ferritic steels (like Grade 409 or 410S).

Why use this for fins?

• Oxidation Resistance: Chromium forms a protective oxide layer (Cr₂O₃) on the surface, which prevents rapid scaling and degradation in high-temperature environments (e.g., furnace flue gases).
• Cost-Effectiveness: While the base tube needs to withstand internal pressure and corrosion from the process fluid, the fins primarily need to resist the external atmosphere. Using a specialized heat-resistant steel for the fins is often more economical than using the more expensive TP321H for the entire finned surface, while still providing excellent service life.

In essence, you specify and use an ASTM A312 TP321H HFW Solid Finned Tube with 11-13Cr Fins when you need a reliable, efficient, and long-lasting heat transfer solution in one of the most demanding industrial settings. It is the material of choice for critical heat recovery applications where failure is not an option due to the extreme costs of downtime and replacement.

Core Application: High-Temperature, High-Pressure Heat Recovery

This finned tube is engineered for situations where standard carbon steel or even basic stainless steel tubes would quickly fail. The combination of the TP321H core tube and the 11-13Cr fins creates a component that excels in:

• High-Temperature Service: Sustained operation at metal temperatures typically above 1000°F (538°C), where creep strength (the gradual deformation of material under constant stress) becomes a critical design factor.
• Corrosive & Oxidizing Environments: Exposure to flue gases, combustion products, and other aggressive atmospheres.
• High Internal Pressure: The core tube must contain a process fluid (usually water, steam, or a process gas) at high pressure.

Specific Industries and Equipment

You will find this tube in the Convection Sections of the following critical industrial units:

1. Heat Recovery Steam Generators (HRSGs)

What it does: Captures waste heat from the exhaust of a gas turbine to produce steam for power generation or process use.

2. Chemical & Petrochemical Process Heaters/Furnaces

What it does: Heats process fluids (e.g., crude oil, hydrocarbons) to very high temperatures for reactions like cracking or reforming.

3. Refinery Fired Heaters

What it does: Similar to process heaters, these are critical units in oil refineries for distillation, hydrotreating, and coking processes.

4. Waste Incineration & Biomass Boilers

What it does: Generates steam by burning waste or biomass. The flue gases from these sources are often highly corrosive due to the presence of chlorides, sulfurs, and other aggressive compounds.

5. Catalytic Cracking Units (FCCU)

What it does: A key unit in refineries that breaks down heavy gas oils into gasoline and other lighter products. It involves intense heat and catalyst circulation.