Amardeep Steel Center is a premier manufacturer, supplier, and exporter of high-performance Stainless Steel 321 Buttweld Fittings. Engineered specifically for high-temperature service, our fittings offer an exceptional combination of strength, stability, and resistance to corrosion. As a leading stockist, we provide a comprehensive range of ASTM A403 WP321 fittings, meticulously produced to meet the rigorous demands of critical industries. Our commitment to quality ensures that every elbow, tee, and reducer delivers long-lasting, reliable performance where other grades would falter.
Leveraging advanced manufacturing and a vast inventory, we are your trusted partner for certified, titanium-stabilized piping solutions that stand up to the heat.
What Are Stainless Steel 321 Buttweld Fittings?
Stainless Steel 321 Buttweld Fittings are crucial piping components used to alter the direction of flow, create branches, or change the diameter within a piping system. These fittings are joined to pipes via butt welding, which creates a strong, contiguous, and leak-proof connection integral to the pipeline's structure. What sets this grade apart is its unique chemical composition, specifically the addition of Titanium (Ti) as a stabilizing element.
Grade 321 (UNS S32100) is a titanium-stabilized austenitic stainless steel, fundamentally a variation of the common Grade 304. This stabilization is its most significant feature. When standard austenitic stainless steels like 304 are exposed to temperatures in the carbide precipitation range of 427°C to 816°C (800°F to 1500°F), chromium carbides can form at the grain boundaries. This process, known as sensitization, depletes the chromium from the surrounding area, making the steel susceptible to intergranular corrosion.
ASTM A403 WP321 fittings combat this issue directly. Titanium has a stronger affinity for carbon than chromium does. It preferentially forms stable titanium carbides, leaving the chromium in solution to maintain the steel's protective passive layer. This makes SS 321 butt weld fittings an excellent choice for applications involving intermittent heating within the sensitization range, or for welded components that cannot be post-weld annealed.
Table of Contents
- Stainless Steel 321 Buttweld Fittings Specifications
- Chemical Composition & Mechanical Properties of Stainless Steel 321 Buttweld Fittings
- Mechanical Properties of Stainless Steel 321 Buttweld Fittings
- Heat Treatment & Tolerances of Stainless Steel 321 Buttweld Fittings
- Dimensional Tolerances of Stainless Steel 321 Buttweld Fittings
- Types & Forms of Stainless Steel 321 Buttweld Fittings
- Applications & Industries Served of Stainless Steel 321 Buttweld Fittings
- Why Choose Amardeep Steel for Stainless Steel 321 Buttweld Fittings?
- Related Products
- Get a Competitive Price
Stainless Steel 321 Buttweld Fittings Specifications
Our entire range of ASME B16.9 WP321 Butt Weld Fittings is manufactured and tested in strict adherence to international standards, ensuring complete compliance and reliability for your projects.
|
Specification |
Details |
|---|---|
|
Specifications |
ASTM A403 / ASME SA403 |
|
Grade |
WP321 (UNS S32100) |
|
Dimensions |
ASME/ANSI B16.9, ASME B16.28, MSS-SP-43, MSS-SP-79 |
|
Size Range |
1/2" NB to 48" NB |
|
Type |
Seamless / Welded / Fabricated |
|
Wall Thickness |
Sch 5s, Sch 10s, Sch 40s, Sch 80s, Sch 160s, Sch XXS |
|
Bending Radius |
R=1D, 2D, 3D, 5D, 6D, 8D, 10D or Custom |
|
Testing |
Radiography Testing (for Welded variant), PMI, Hardness Test |
Chemical Composition & Mechanical Properties of Stainless Steel 321 Buttweld Fittings
The performance of UNS S32100 butt weld fittings in high-temperature and corrosive environments is a direct result of their carefully controlled chemical balance and robust mechanical characteristics.
Chemical Composition (wt %)
|
Grade |
C |
Mn |
Si |
P |
S |
Cr |
Ni |
Ti |
|---|---|---|---|---|---|---|---|---|
|
SS 321 (UNS S32100) |
0.08 max |
2.0 max |
0.75 max |
0.045 max |
0.030 max |
17.0 - 19.0 |
9.0 - 12.0 |
≥ 5 x C |
Mechanical Properties of Stainless Steel 321 Buttweld Fittings
|
Property |
Typical Value |
|---|---|
|
Tensile Strength |
515 MPa (75,000 psi) |
|
Yield Strength (0.2% Offset) |
205 MPa (30,000 psi) |
|
Elongation in 2" |
40% |
|
Hardness (Brinell) |
217 Max |
|
Density |
8.03 g/cm³ |
|
Melting Point |
1398 - 1457 °C (2550 - 2650 °F) |
Heat Treatment & Tolerances of Stainless Steel 321 Buttweld Fittings
We implement rigorous process controls to ensure every fitting we produce offers optimal performance and perfect dimensional accuracy for easy installation.
Heat Treatment Requirements of Stainless Steel 321 Buttweld Fittings
To maximize their performance, Stainless Steel 321 Buttweld Fittings undergo a specific heat treatment. They are typically supplied in the solution-annealed condition, which involves heating to a temperature between 950°C and 1120°C (1740°F and 2050°F) followed by rapid cooling. This process dissolves any carbides and relieves internal stresses from the manufacturing process. Additionally, a stabilization heat treatment may be performed at around 870-900°C (1600-1650°F) to precipitate the titanium carbides, ensuring maximum resistance to intergranular corrosion during subsequent high-temperature service.
Dimensional Tolerances of Stainless Steel 321 Buttweld Fittings
All our fittings strictly conform to the dimensional tolerances specified in ASME B16.9. This standard meticulously governs the center-to-face dimensions, angles, bevels, and overall geometry. Adhering to these tight tolerances is crucial for ensuring a perfect fit-up and alignment during on-site welding, which significantly simplifies the installation process and prevents the creation of residual stress points in the piping system.
Types & Forms of Stainless Steel 321 Buttweld Fittings
Amardeep Steel Center offers a complete range of 321 Stainless Steel Pipe Fittings to meet the diverse needs of any piping configuration.
- SS 321 90° & 45° Elbows (Long & Short Radius): For creating standard directional changes in a pipeline.
- SS 321 Equal & Reducing Tees: To create 90-degree branches of the same or smaller diameter from the main pipe.
- SS 321 Concentric & Eccentric Reducers: To smoothly connect pipes of different diameters along a common or offset centerline.
- SS 321 End Caps: For providing a secure, permanent seal at the end of a pipeline.
- SS 321 Stub Ends (Lap Joints): Used in conjunction with lap joint flanges to facilitate easier alignment and disassembly of flanged points.
- SS 321 Pipe Bends: Custom-fabricated bends with radii like 3D, 5D, and 10D for applications requiring gradual flow changes to minimize pressure drop.
- SS 321 Crosses: Four-way fittings used to connect four intersecting pipe runs.
Applications & Industries Served of Stainless Steel 321 Buttweld Fittings
The unique properties of SS 321 butt weld fittings make them the material of choice for a range of demanding, high-temperature industries:
- Aerospace Industry: Extensively used for aircraft exhaust manifolds, collector rings, and jet engine components where high-temperature strength and oxidation resistance are critical.
- Chemical Processing: In equipment and piping that handles hot corrosive media, especially where resistance to polythionic acid stress corrosion cracking (PASCC) is required.
- Power Generation: For high-temperature steam lines, superheater and reheater tubes, and expansion bellows.
- Petrochemical & Refining: In furnace parts, radiant superheaters, and high-temperature heat exchangers.
- Waste Heat Recovery & Incineration: For components exposed to high-temperature corrosive flue gases.
- Food Processing: In equipment that requires frequent high-temperature sterilization cycles.
Why Choose Amardeep Steel for Stainless Steel 321 Buttweld Fittings?
- Manufacturing Excellence: Our in-house production capabilities provide us with complete control over the manufacturing process, from raw material sourcing to final inspection. This ensures every Stainless Steel 321 Buttweld Fittings we produce has consistent wall thickness, superior finish, and full compliance with specifications.
- Global Exports: We are a globally recognized exporter, serving a diverse customer base in the USA, Canada, UAE, Saudi Arabia, Europe, and Southeast Asia. Our deep understanding of international standards and logistics guarantees a seamless procurement process.
- Fast Turnaround: We maintain an extensive inventory of standard 321 Stainless Steel Pipe Fittings in various sizes and schedules, ready for immediate dispatch to meet your project deadlines.
- Certified Quality: As an ISO 9001:2015 certified manufacturer, quality is ingrained in our culture. All fittings are supplied with an EN 10204 3.1 Material Test Certificate (MTC) for full traceability. We also arrange third-party inspections from reputable agencies like TUV, DNV, and Lloyd’s upon customer request.
- Technical Support: Our team of experienced metallurgists and engineers acts as a valuable resource for our clients. We provide expert guidance on material selection, application design, and technical queries to ensure you get the best solution for your needs.
Related Products
- 321/321H Pipe Fittings
- Stainless Steel 321 Forged Fittings
- Stainless Steel 321H Forged Fittings
- Stainless Steel 321H Buttweld Fittings
Get Your Stainless Steel 321 Buttweld Fittings Price
Ready to specify Stainless Steel 321 Buttweld Fittings for your next project? Contact Amardeep Steel Center today for a fast, no-obligation quote. Our knowledgeable sales team will provide a competitive price and a delivery schedule tailored to your requirements.
Frequently Asked Questions (FAQ's)
1. What is the main difference between SS 321 and SS 321H fittings?
The primary difference is the carbon content. SS 321H has a higher specified carbon range (0.04% - 0.10%), which provides superior high-temperature strength and creep resistance, making it the preferred choice for applications operating above 538°C (1000°F). SS 321 has a maximum carbon content of 0.08%.
2. Why should I choose 321 butt weld fittings over 304?
You should choose 321 over 304 for applications involving service temperatures between 427°C and 816°C (800°F - 1500°F). The titanium in 321 prevents intergranular corrosion in this range, a problem that would affect standard 304, especially in welded conditions.
3. Are these fittings easy to weld?
Yes, 321 Stainless Steel Pipe Fittings are readily weldable by all common fusion and resistance methods. For optimal corrosion resistance in the weld, it is recommended to use a filler metal like AWS E/ER 347, which is stabilized with Niobium and performs a similar function to Titanium.
4. What is the purpose of the stabilization heat treatment?
The stabilization heat treatment is performed after the initial solution anneal. It involves heating the material to a specific temperature to intentionally precipitate titanium carbides. This "locks up" the carbon with titanium, ensuring no chromium carbides can form later during high-temperature service, thereby providing maximum long-term protection against intergranular corrosion.
5. Do you provide Material Test Certificates (MTCs) with your fittings?
Absolutely. Every order of Stainless Steel 321 Buttweld Fittings is dispatched with an EN 10204 3.1 MTC. This certificate offers full traceability and confirms the material's chemical composition, mechanical properties, and compliance with the ordered specifications.
