Why Choose Us as Your Duplex Flange Supplier?
Selecting the right supplier for duplex flanges is a strategic decision that impacts the
safety, efficiency, and cost-effectiveness of your operations. CEBEX STEEL INDIA stands
out as a preferred partner due to our unwavering commitment to quality, technical expertise,
and customer satisfaction. We are ISO 9001:2015 and PED certified, reflecting our adherence
to global quality management systems and our ability to meet the requirements of
international projects.
Our in-house laboratory is equipped to perform a comprehensive range of mechanical, chemical,
and non-destructive tests, ensuring that every batch of flanges meets or exceeds client
specifications. We maintain full traceability from raw material to finished product, and all
shipments are accompanied by detailed mill test certificates (EN 10204 3.1/3.2), NDT reports,
and compliance documentation. Our export team is experienced in handling complex logistics,
documentation, and packing requirements, making us a reliable partner for buyers in Africa,
the Middle East, Southeast Asia, and beyond.
Product Overview & Key Features
Our duplex and super duplex flanges are manufactured using premium raw materials sourced from
approved mills, and every stage of production is closely monitored for quality assurance.
We offer a comprehensive range of flange types, sizes, and pressure ratings, suitable for
a wide variety of industrial applications. Whether your requirement is for standard ASME
flanges or custom-designed solutions, our engineering team is equipped to deliver with
precision and speed.
The following table summarizes the key features and specifications of our duplex flanges:
| Parameter |
Details |
| Product Name |
Duplex Stainless Steel Flanges |
| Common Grade |
Duplex 2205 (UNS S31803 / S32205) |
| Other Available Grades |
ASTM A182 F51, F53, F55, F60 |
| Material Standard |
ASTM A182 / ASME SA182 |
| Yield Strength (Min.) |
450 MPa (Approx.) |
| Tensile Strength (Min.) |
620 MPa |
Types of Duplex Flanges We Manufacture
Our product portfolio covers the full spectrum of duplex and super duplex flanges, each
designed for specific applications and operating conditions. Weld neck flanges are preferred
for high-pressure systems due to their robust design and ability to withstand extreme
temperature fluctuations. Slip-on flanges offer ease of installation and are widely used
in lower-pressure applications. Blind flanges are essential for sealing off piping systems
or pressure vessel openings, while socket weld and threaded flanges provide reliable
connections for smaller diameter pipes.
We also manufacture lap joint, orifice, spectacle blind, long weld neck, and reducing
flanges, as well as custom flanges based on client drawings and specifications. Our
engineering team works closely with clients to ensure that every flange meets the precise
requirements of their project, from material selection to dimensional tolerances.
Grades, Materials & International Standards
Material selection is a critical factor in flange performance, especially in corrosive or
high-pressure environments. We offer duplex and super duplex flanges in a wide range of
grades, each compliant with relevant international standards.
| Duplex Grade |
Typical Applications |
Standards |
| F51 (2205) |
Oil & gas, chemical, marine, desalination |
ASTM A182, ASME SA182 |
| F53 (2507) |
Offshore, petrochemical, high chloride environments |
ASTM A182, ASME SA182 |
| F55 |
Aggressive chemical, acid, and chloride environments |
ASTM A182, ASME SA182 |
| F44 |
Pulp & paper, chemical, food processing |
ASTM A182, ASME SA182 |
All materials are sourced from reputed mills and are fully traceable, with heat numbers and
batch records maintained for every order.
Chemical Composition & Mechanical Properties
Every duplex flange is supplied with comprehensive test certificates, including chemical
composition and mechanical property reports. This ensures full compliance with project
specifications and international codes. Our in-house laboratory conducts spectrographic
analysis, tensile testing, hardness testing, and non-destructive examinations such as
ultrasonic and radiographic testing.
Chemical Composition (% by Weight)
| Grade |
C Max |
Mn Max |
Si Max |
P Max |
S Max |
Cr (%) |
Ni (%) |
Mo (%) |
N (%) |
| F51 (2205) |
0.03 |
2.00 |
1.00 |
0.030 |
0.020 |
21.0–23.0 |
4.5–6.5 |
2.5–3.5 |
0.08–0.20 |
| F53 (2507) |
0.03 |
1.20 |
0.80 |
0.035 |
0.020 |
24.0–26.0 |
6.0–8.0 |
3.0–5.0 |
0.24–0.32 |
| F55 |
0.03 |
1.00 |
0.80 |
0.030 |
0.020 |
24.0–27.0 |
6.0–8.0 |
3.0–5.0 |
0.20–0.30 |
| F44 (6Mo) |
0.02 |
1.00 |
0.80 |
0.040 |
0.030 |
19.5–20.5 |
17.5–18.5 |
6.0–6.5 |
0.18–0.25 |
Mechanical Properties
| Grade |
Tensile Strength (MPa) Min |
Yield Strength (MPa) Min |
Elongation (%) Min |
Hardness (HB) Max |
| F51 (2205) |
620 |
450 |
25 |
293 |
| F53 (2507) |
800 |
550 |
15 |
310 |
| F55 |
795 |
550 |
15 |
310 |
| F44 (6Mo) |
650 |
300 |
35 |
290 |
Dimensions, Sizes & Weight Chart
We manufacture duplex flanges in a wide range of dimensions, from ½" NB to
48" NB, with pressure ratings from Class 150 to Class 2500 and PN6 to PN400. Our
production is fully compliant with ASME B16.5, B16.47, EN 1092-1, DIN, and other
international standards. The following table illustrates typical dimensions for weld neck
flanges as per ASME B16.5:
| Size (NB) |
OD (mm) |
Thickness (mm) |
Bolt Circle (mm) |
No. of Bolts |
| ½" |
89 |
11.2 |
60.3 |
4 |
| 1" |
114 |
13.5 |
79.4 |
4 |
| 2" |
152 |
17.5 |
120.7 |
8 |
| 4" |
229 |
24.3 |
190.5 |
8 |
| 8" |
343 |
30.2 |
298.5 |
8 |
Custom dimensions and special machining are available upon request.
Applications & Industries Served
Our duplex and super duplex flanges are trusted by leading companies and EPC contractors in
a diverse range of industries. In the oil and gas sector, our products are used in upstream,
midstream, and downstream applications, including pipeline construction, refinery upgrades,
and offshore platforms. Power generation clients rely on our flanges for thermal, nuclear,
and renewable energy projects, where safety and reliability are paramount.
Shipbuilding and marine engineering firms specify our flanges for their corrosion resistance
and mechanical strength, while chemical and petrochemical plants value our ability to supply
exotic alloy flanges for aggressive process environments.
We also serve the cement, construction, water treatment, mining, and food processing
industries, providing tailored solutions for each sector's unique requirements. Our
experience with international projects ensures that we understand the documentation,
certification, and logistical needs of global buyers.
Exporting Duplex Flanges to Africa
As a leading Duplex Flanges Manufacturer in India, we have built a strong reputation for
supplying high-quality flanges to major projects across Africa. Our export team understands
the unique requirements of African industries and ensures smooth, timely deliveries with
complete documentation and compliance. From oil and gas to power and infrastructure, our
flanges are trusted by clients in Nigeria, Egypt, Kenya, South Africa, Ethiopia and beyond.
To learn more about our specialized solutions for the continent, visit our
Africa Duplex Flanges Exporter page.
Related Alloy Flanges – Stainless Steel, Duplex, Super Duplex, Hastelloy, Inconel, Monel, Titanium, Copper Nickel, Alloy Steel
In addition to Duplex Flanges, we also manufacture and export Stainless Steel Flanges, Super Duplex Flanges, Hastelloy Flanges, Inconel Flanges, and Monel Flanges. These high-performance alloy flanges are engineered for demanding industrial environments requiring superior corrosion resistance, high mechanical strength, and reliable performance under extreme temperature and pressure conditions.
Our technical team ensures accurate material selection and full compliance with international standards to meet the specific requirements of your project.
Browse our full range:
Why Choose CEBEX STEEL INDIA?
Our clients choose CEBEX STEEL INDIA for our technical expertise, commitment to quality, and
responsive service. We offer direct-from-manufacturer pricing, flexible order quantities,
and comprehensive after-sales support. Our engineering team is available to assist with
material selection, specification review, and custom design, ensuring that you receive the
optimal solution for your application.
