ASTM A182 F321 Stainless Steel Flanges Supplier ASME B16.5 Weld Neck Flange

The ASTM A182 F321 Stainless Steel Flange is a high-performance, forged piping component designed for demanding high-temperature and corrosive service environments. As a variant of austenitic stainless steel, Grade F321 is stabilized with titanium, which provides superior resistance to intergranular corrosion and maintains excellent mechanical strength at elevated temperatures. These flanges are manufactured in accordance with stringent international standards, including ASTM A182/A182M, and are commonly used in conjunction with dimensional standards such as ASME B16.5. They are available in various types (like Weld Neck), pressure classes (e.g., 150LB to 2500LB), and sizes to meet diverse industrial piping system requirements.

• Standard Specification: ASTM A182 / ASME SA-182.

• Common Dimensional Standard: ASME B16.5.

• Material Grade: UNS S32100 / Alloy 321.

• Key Characteristic: The addition of Titanium (Ti) (at least 5 times the Carbon content) stabilizes the alloy against carbide precipitation during welding and high-temperature exposure (450-850°C), effectively preventing chromium depletion at grain boundaries and subsequent intergranular corrosion.

• Common Types: Weld Neck (WN), Slip-On, Blind, etc., available from suppliers.

• Pressure Ratings: Available in a wide range, typically from Class 150 to Class 2500.

The following tables summarize the key composition and room-temperature mechanical properties as per the standard. Note that for high-temperature performance, mechanical strength values vary with temperature.

Table 1: Chemical Composition (Weight %) - ASTM A182 F321

Table 2: Typical Room-Temperature Mechanical Properties

• Important Note on High-Temperature Strength: The mechanical strength of F321 is retained at high temperatures. For example, at 1200°F (649°C), its tensile strength is approximately 45.5 ksi, and yield strength is about 16 ksi.

Thanks to its excellent high-temperature strength and corrosion resistance, ASTM A182 F321 flanges are widely used in critical industries:

• Petrochemical & Chemical Processing: Ideal for refinery piping, heat exchangers, and vessels handling corrosive media at elevated temperatures.

• Power Generation: Suitable for boiler systems, steam lines, and FGD (Flue Gas Desulfurization) systems where thermal stability is crucial.

• Oil & Gas: Used in upstream and downstream equipment, including offshore platforms and subsea pipelines, where resistance to sour environments and high pressure is needed.

• High-Temperature Utility Piping: Commonly applied in superheated steam and hot oil lines.