ASTM A312 TP321 (1.4541) Stainless Steel Seamless Fin Tube For Condensers

I. Product Overview

The ASTM A312 TP321 serrated fin tube is a high-performance heat transfer component designed for demanding high-temperature applications. This tube is titanium-stabilized, offering superior corrosion resistance and sensitization resistance in environments subject to thermal cycling and exposure to corrosive gases within the sensitization temperature range.

Manufactured from ASTM A312 TP321 (austenitic stainless steel stabilized with titanium), this tube is designed to withstand harsh conditions. The titanium content (≥5×C) prevents chromium carbide precipitation at grain boundaries, thus ensuring resistance to intergranular corrosion — a critical feature in welded assemblies exposed to temperatures between 450°C and 850°C. This makes TP321 ideal for applications where post-weld heat treatment is not possible.

Capable of withstanding intermittent metal temperatures up to 815°C (1500°F), and continuous service temperatures around 700°C (1292°F), this tube excels in refineries, chemical plants, and power generation systems, where heat transfer efficiency and corrosion resistance are critical.

II. Chemical & Mechanical Properties of ASTM A312 TP321 Tubes

Chemical Composition:

Mechanical Properties (Base Tube):

III. Comparison with Similar Products

ASTM A312 TP321 vs. ASTM A312 TP304 & TP347H:

1.TP321 vs. TP304: TP304 is a more cost-effective, general-purpose stainless steel, but it is vulnerable to sensitization in the 450°C-850°C range. TP321, with its titanium stabilization, is ideal for welded applications that operate within this temperature zone and provides excellent resistance to intergranular corrosion.

2.TP321 vs. TP347H: TP347H is stabilized with niobium and offers higher creep strength at temperatures above 650°C, making it preferable for superheater applications. TP321, however, remains a more economical option for a wide range of high-temperature corrosive services, especially where titanium stabilization is critical.

IV. Key Applications of ASTM A312 TP321 Serrated Fin Tubes

1.Petrochemical Fired Heaters: Used in convection sections of ethylene crackers, reformer heaters, and crude heaters, particularly in applications where the tube skin temperature cycles within the sensitization range.

2.Refinery Process Heaters: Used in vacuum heaters, coker heaters, and other high-temperature systems that process sulfur-bearing feedstocks exposed to corrosive flue gases.

3.Chemical Process Waste Heat Boilers: Ideal for recovering heat from corrosive process gas streams at elevated temperatures in chemical plants.

4.Power Generation: Utilized in high-temperature heat exchangers and economizers in power plants burning fuels that generate corrosive combustion byproducts.

5.Sulfur Recovery Units (SRUs): Employed in Claus plants for tail gas reheating, where resistance to sulfur compounds is crucial.

V. FAQ Section

Q1: Why is TP321 preferred over TP304 for finned tubes?
A1: TP304 is susceptible to sensitization and intergranular corrosion when exposed to temperatures between 450°C and 850°C, especially after welding. TP321, with titanium stabilization, prevents these issues and ensures reliable performance in such environments without needing post-weld heat treatment.

Q2: What is the maximum continuous service temperature for ASTM A312 TP321 serrated fin tubes?
A2: TP321 serrated fin tubes can withstand continuous service temperatures up to approximately 700°C (1292°F) and intermittent service up to 815°C (1500°F). For specific applications, pressure, stress, and environmental factors should be considered per applicable codes like ASME BPVC.

Q3: Why is the serrated fin design particularly beneficial for TP321 tubes?
A3: The serrated fin design reduces thermal stress on welds and minimizes fouling. The notches prevent the formation of continuous ash or soot layers, improving heat transfer efficiency and making the tube more resistant to high-temperature corrosion and fouling.

Q4: What are the equivalents of ASTM A312 TP321?

A4: