Amardeep Steel Center is a premier manufacturer, supplier, and exporter of high-performance 321/321H Pipe Fittings. Specifically engineered for high-temperature service, our fittings offer an exceptional combination of strength and resistance to corrosion, making them a top choice for demanding industrial applications. We produce a full range of Stainless Steel 321 Pipe Fittings and Stainless Steel 321H Pipe Fittings in compliance with global standards like ASTM A403.
For systems that operate in the chromium carbide precipitation range, our fittings provide the stability and reliability needed to ensure long-term, safe operation. We are dedicated to delivering quality you can trust for your most critical high-temperature processes.
What Are 321/321H Pipe Fittings?
321/321H Pipe Fittings are specialized components used to connect, direct, and branch piping systems that are exposed to high temperatures. What makes these fittings unique is the addition of titanium as a stabilizing element. This is crucial because, at temperatures between 425°C and 850°C (800°F and 1560°F), standard austenitic stainless steels can suffer from "sensitization," where chromium carbides form and lead to intergranular corrosion. The titanium in Grade 321 "stabilizes" the carbon, preventing this from happening and preserving the material's corrosion resistance even after prolonged exposure to high heat.
The two variants in this grade family are designed for specific high-temperature needs:
- Stainless Steel 321 Pipe Fittings (SS 321 Pipe Fittings): This is the standard titanium-stabilized grade. It offers excellent resistance to intergranular corrosion and is suitable for a wide range of high-temperature applications.
- Stainless Steel 321H Pipe Fittings (SS 321H Pipe Fittings): The 'H' denotes a higher carbon content. This modification gives 321H stainless steel fittings enhanced high-temperature strength and improved creep resistance, making them the preferred choice for structural applications at temperatures above 538°C (1000°F).
These fittings are governed by specifications like ASTM A403, with designations such as ASTM A403 WP321 fittings and ASTM A403 WP321H fittings, ensuring they meet the strict requirements for high-temperature pressure service.
Table of Contents
- 321/321H Pipe Fittings Specifications
- Chemical Composition & Mechanical Properties of 321/321H Pipe Fittings
- Mechanical Properties of 321/321H Pipe Fittings
- Heat Treatment & Tolerances of 321/321H Pipe Fittings
- Dimensional Tolerances of 321/321H Pipe Fittings
- Types & Forms of 321/321H Pipe Fittings
- Applications & Industries Served of 321/321H Pipe Fittings
- Why Choose Amardeep Steel for 321/321H Pipe Fittings?
- Related Products
- Get a Competitive Price
321/321H Pipe Fittings Specifications
At Amardeep Steel Center, every one of our 321 stainless steel pipe fittings is manufactured to precise specifications. This ensures complete interchangeability, compliance with global engineering codes, and a perfect fit for your high-temperature systems.
|
Specification |
Details |
|---|---|
|
Standard |
ASTM A403 / ASME SA403 |
|
Grades |
WP321, WP321H |
|
Types |
Seamless / Welded / Fabricated |
|
Buttweld Fittings Size |
1/2" to 48" |
|
Forged Fittings Size |
1/4” to 4” |
|
Bending Radius |
R=1D, 2D, 3D, 5D, 6D, 8D, 10D or Custom |
|
Wall Thickness / Schedule |
Sch 5s, 10s, 40s, 80s, 10, 20, 40, STD, 60, 80, XS, 100, 120, 140, 160, XXS |
|
Pressure Class (Forged) |
2000 LBS, 3000 LBS, 6000 LBS, 9000 LBS |
|
Dimensions |
ASME/ANSI B16.9, ASME B16.28, MSS-SP-43, MSS SP-75 |
Chemical Composition & Mechanical Properties of 321/321H Pipe Fittings
The exceptional performance of our fittings is a direct result of their carefully balanced chemical composition and robust mechanical properties. We conduct rigorous testing on every batch to ensure they meet or exceed all required standards.
Chemical Composition (wt %)
The addition of titanium is the key to this alloy's stability at high temperatures.
|
Grade |
C |
Mn |
Si |
P |
S |
Cr |
Ni |
Ti |
|---|---|---|---|---|---|---|---|---|
|
SS 321 (WP321) |
0.08 max |
2.00 max |
0.75 max |
0.045 max |
0.030 max |
17.0-19.0 |
9.0-12.0 |
5 x C min |
|
SS 321H (WP321H) |
0.04-0.10 |
2.00 max |
0.75 max |
0.045 max |
0.030 max |
17.0-19.0 |
9.0-12.0 |
4 x C min |
Mechanical Properties of 321/321H Pipe Fittings
These properties demonstrate the material's ability to maintain its strength and integrity under high-temperature stress.
|
Grade |
Tensile Strength (min) |
Yield Strength (min) |
Elongation in 2" (min) |
Hardness (max) |
|---|---|---|---|---|
|
ksi (MPa) |
ksi (MPa) |
% |
Rockwell B |
|
|
WP321/321H |
75 (515) |
30 (205) |
40 |
95 |
Heat Treatment & Tolerances of 321/321H Pipe Fittings
Two of the most critical steps in producing high-quality fittings are the heat treatment process and the control of dimensional tolerances.
Heat Treatment Requirements of 321/321H Pipe Fittings
All our 321/321H Pipe Fittings are supplied in a stabilized, heat-treated condition. The typical heat treatment is a stabilizing anneal, where the fittings are heated to a temperature between 870°C and 900°C (1600°F and 1650°F). This process serves two purposes: it relieves stresses from manufacturing and it causes titanium carbides to precipitate, which "stabilizes" the material and prevents the formation of harmful chromium carbides during subsequent high-temperature service.
Dimensional Tolerances of 321/321H Pipe Fittings
A precise fit is essential for system integrity. We manufacture our fittings to the strict dimensional standards of ASME B16.9 (for buttweld fittings) and ASME B16.11 (for forged fittings). This guarantees that every angle, diameter, and face-to-center dimension is accurate, ensuring a smooth installation and a reliable, leak-free connection
Types & Forms of 321/321H Pipe Fittings
As a leading manufacturer, Amardeep Steel Center produces a comprehensive range of high temperature SS 321 pipe fittings to meet any project specification.
- Elbows (45°, 90°, 180°): To change the direction of a pipeline.
- Tees (Equal & Reducing): For creating 90-degree branches.
- Reducers (Concentric & Eccentric): For connecting pipes of different sizes.
- Caps: To securely seal the end of a pipeline.
- Stub Ends: Used with lap joint flanges for an economical flanged connection.
- Pipe Bends: Custom bends with larger radii for gradual directional changes.
- Couplings, Nipples, and Crosses: A full suite of components for all connection needs.
Applications & Industries Served of 321/321H Pipe Fittings
The unique high-temperature properties of SS 321H fittings for heat exchangers and other applications make them essential in several key industries:
- Aerospace: For aircraft exhaust manifolds and piston engine components.
- Chemical Processing: For equipment that operates within the carbide precipitation temperature range.
- Power Generation: In expansion joints, superheaters, and afterburner parts.
- Heat Exchangers: For tubes and shells exposed to high temperatures.
- Furnaces: For parts, radiant tubes, and other high-temperature equipment.
- Waste Treatment: In thermal oxidizers and incineration systems.
Why Choose Amardeep Steel for 321/321H Pipe Fittings?
When you partner with Amardeep Steel, you are choosing a supplier committed to quality, reliability, and customer satisfaction. Here’s what makes us different:
- Manufacturing Excellence: Our in-house manufacturing facilities give us complete control over the production process, ensuring every fitting has consistent wall thickness, a superior finish, and meets our stringent quality standards.
- Global Exports: As a trusted exporter, we have a long history of serving customers in the USA, Canada, UAE, Saudi Arabia, Europe, and Southeast Asia. Our logistics team ensures on-time, secure delivery anywhere in the world.
- Fast Turnaround: We maintain a large stock of standard 321/321H Pipe Fittings, ready for immediate shipment. This allows us to fulfill urgent orders and keep your projects running smoothly.
- Certified Quality: We stand by our products. As an ISO 9001:2015 certified company, we supply all our fittings with a Mill Test Certificate (MTC) as per EN 10204 3.1. We also facilitate third-party inspections from reputable agencies like TUV, DNV, and Lloyd’s.
- Technical Support: Our team of expert metallurgists and engineers is available 24/7 to provide technical guidance. Whether you need help with material selection or application-specific designs, we are here to support you.
Related Products
- Stainless Steel 321 Butt weld Fittings
- Stainless Steel 321H Butt weld Fittings
- Stainless Steel 321 Forged Fittings
- Stainless Steel 321H Forged Fittings
Get Your 321/321H Pipe Fittings Price
Ready to order your 321/321H Pipe Fittings? Get a competitive price from an industry leader you can trust. Contact our sales team today for a fast, no-obligation quote and let us provide the high-performance fittings your project demands.
Frequently Asked Questions (FAQ's)
1. What is the main benefit of using Grade 321 over Grade 304?
The main benefit is its resistance to intergranular corrosion at high temperatures. The titanium in Grade 321 prevents chromium carbide from forming when the steel is exposed to temperatures between 425-850°C, a problem that can affect Grade 304. This makes 321 stainless steel pipe fittings much more reliable for high-temperature service.
2. When should I use 321H instead of 321?
You should choose 321H stainless steel fittings for applications where high-temperature strength and creep resistance are critical, typically at temperatures above 538°C (1000°F). The higher carbon content in 321H provides superior mechanical properties in these extreme conditions.
3. Can Grade 321/321H fittings be welded?
Yes, both grades are readily weldable using common fusion and resistance methods. A post-weld heat treatment is not necessary to restore their corrosion resistance.
4. What certifications do you provide with your fittings?
We supply a Mill Test Certificate (MTC) in accordance with EN 10204 3.1 with every order. This certificate provides full traceability and documents the material's precise chemical composition and mechanical properties, ensuring it meets all required standards.
5. How quickly can I get my order?
For standard items in our stock, we can typically ship within 24 to 48 hours. For custom or large-volume orders, we will provide a specific delivery schedule with your quote. Our efficient manufacturing processes ensure we can meet even the most demanding project timelines.
