ASTM A312 TP321H Solid Fin Tube for Heat Exchangers and HRSG System

ASTM A312 TP321H Solid Fin Tube Key Features and Principles

• Material Composition: TP321H is a modified version of TP321, with a higher carbon content (C: 0.040.10) for improved high-temperature performance. It is stabilized with titanium (Ti: =4C0.60), which enhances its resistance to intergranular corrosion.
• Mechanical Properties: This grade offers excellent mechanical strength at both high and low temperatures. Typical required mechanical properties include:

Tensile Strength (σb): ≥ 520 MPa

Yield Strength (σ0.2): ≥ 205 MPa

Elongation (δ5): ≥ 40%

• Manufacturing and Heat Treatment: The seamless tubes are manufactured through processes like cold rolling or cold drawing and are delivered in a heat-treated and pickled condition-8. A solution treatment at a high temperature (≥ 2000°F / 1100°C) is required to ensure the material's properties.
• The Principle of Solid Fin Tubes: A solid fin tube is manufactured by mechanically winding a solid strip of metal (often aluminum or stainless steel) around the circumference of the base TP321H pipe and bonding it securely. This design significantly increases the external surface area of the tube. The principle is to enhance heat transfer efficiency: the base tube carries the high-temperature or corrosive fluid, and the fins dissipate the heat to the surrounding air or gas much more effectively than a bare pipe could.

ASTM A312 TP321H Solid Fin Tube Common Uses and Applications

The TP321H grade is designed for high-temperature service. When made into fin tubes, its primary application is in heat exchangers operating under demanding conditions, such as:

• Heat Exchangers in petroleum refining and chemical processing plants.
• Boiler Components: Used in large boilers for superheater and reheater sections.
• Other Applications: Also found in industries like power generation, shipbuilding, and environmental protection for various heat transfer tasks.

ASTM A312 TP321H Solid Fin Tube Advantages and Performance

• Superior High-Temperature Performance: The "H" grade designation ensures higher creep and stress rupture strength, making it suitable for long-term service in high-temperature environments ranging from 427°C to 816°C.
• Excellent Corrosion Resistance: It offers good resistance to a wide range of organic and inorganic acids, particularly in oxidizing environments, and has a high resistance to intergranular corrosion.
• Durability and Long Service Life: The combination of high strength and corrosion resistance leads to a longer operational life and reduced maintenance frequency.

ASTM A312 TP321H Solid Fin Tube Important Considerations and FAQs

• What is the difference between TP321 and TP321H?

TP321H has a higher carbon content than TP321, which provides it with better high-temperature strength properties (creep and stress rupture strength) specifically for use in high-temperature service applications like superheaters.

• What testing is performed on these tubes?

The tubes undergo multiple tests to ensure quality, including hydraulic pressure tests, flattening tests, tensile tests, non-destructive testing (eddy current or ultrasonic), and intergranular corrosion tests.

• What should I consider when sourcing TP321H solid fin tubes?

Since the search results lack details on the fins, it is crucial to discuss with the manufacturer:

Fin Material: Typically aluminum for air-cooling, but stainless steel or other alloys may be used for corrosive environments.

Fin Density and Height: This directly impacts the heat transfer surface area and efficiency.

Bonding Integrity: Ensure the bond between the fin and the base tube is robust to maintain thermal efficiency.