China Duplex Stainless Steel Flange Manufacturers Suppliers - Factory Direct Price

Your Professional Duplex Stainless Steel Flange Supplier

Henan Shuangzhong Intelligent Technology Co., Ltd., an expert in precision manufacturing and pipeline system solutions, was founded in 1999. We are a professional manufacturer specializing in precision machining customization, pipeline equipment and pipe fittings customization, as well as the manufacturing and processing of duplex stainless steel flanges.

ASTM A182 F51 Duplex Stainless Steel Forged Flanges
ASTM A182 F51 can be supplied in a wide range of flange configurations ， including:Weld Neck FlangesSlip-On FlangesBlind FlangesSocket Weld FlangesThreaded FlangesLap Joint Flanges
Super Duplex S32750 Flange
Type: SO, SW, BL, WN, LJ, Spectacle, Orifice, etc.Size: 1/2–48, DN10–DN4000Class: 75#–2500#, PN6–PN100Standard: ASME, DIN, EN, JIS, BS
ASTM A182 F55 Stainless Steel Forged Flanges
ASTM A182 F55 Stainless Steel Forged Fittings & Flanges, excellent chloride & sour corrosion resistance, high strength, ideal for offshore and desalination projects.
S31803 Blind Flange
Name：S31803 Blind FlangeTypes: SO, SW, BL, WN, LJ, Spectacle, Orifice, etc.Sizes: 1/2-48, DN10-DN4000Grades: 75-2500, PN6-PN100Standards: ASME, DIN, EN, JIS, BS
Duplex 2205 Flanges
Product name: Duplex 2205 Flanges. Material grade: duplex stainless steel, containing 21-23% chromium, 4.5-6.5% nickel, 2.5-3.5% molybdenum, and 0.08-0.20% nitrogen. Mechanical properties: tensile
Duplex Steel Flanges S32750
Product name: Duplex Steel Flanges S32750. Material properties: S32750 flange (UNS S32750; EN 1.4410) is a super duplex stainless steel containing 24-26% chromium, 6-8% nickel, 3-4% molybdenum, and
Duplex Steel Flanges A182 F52
Product name: Duplex Steel Flanges A182 F52. Material properties: F53 Duplex2507 S32750 flange (UNS S32750; EN 1.4410) is a super duplex stainless steel containing 24-26% chromium, 6-8% nickel, 3-4%
Duplex Steel Flanges S32760
Material：Duplex Steel Flanges S32760 (austenite + ferrite), superior chloride corrosion resistance vs 304/316, tensile strength ≥800MPa. Ideal for high-salt, strong-corrosion scenarios (desalination,
Super Duplex Steel Flanges
Product Name：Super Duplex Steel Flanges. Material：S32250 duplex stainless steel (austenite + ferrite) offers excellent chloride/sulfide resistance and 650-800MPa tensile strength.. Applicable

Why choose us

One-Stop Customized Solutions

We are committed to providing customers with one-stop customized solutions — from design support and precision manufacturing to quality assurance — to meet the diverse needs of various industries for high-performance, high-precision, and high-reliability industrial components.

Certification

We ensure quality through comprehensive system certifications: the company has passed the ISO 9001:2015 quality management system certification and the American Petroleum Institute (API) quality certification system.

Sales Market

Our products have been successfully exported to many countries and regions around the world, including the United States, Canada, Germany, India, Malaysia, Pakistan, the United Arab Emirates, Egypt, and the Middle East. We have earned the trust and praise of overseas customers.

On-Site Quality Supervision

We dispatch professional quality inspection teams to supervise the production of steel pipe fittings and rubber hoses. From raw material entry to the shipment of finished products, we maintain strict quality control throughout the process and accommodate special customer requirements, such as product identification and packaging methods.

Duplex Stainless Steel Flange

Duplex stainless steel flanges are a type of pipe fitting used in various industries for their exceptional strength, durability, and corrosion resistance. This unique material is made up of equal parts austenitic and ferritic stainless steels, giving it the best properties of both while minimizing weaknesses. It is commonly used in high-pressure applications where conventional materials may fail due to stress or corrosion. Additionally, duplex stainless steel flanges have higher toughness and can withstand extreme temperatures, making them ideal for use in harsh environments such as offshore oil rigs and chemical plants.

But their ability to resist pitting and crevice corrosion sets duplex stainless steel flanges apart from other materials. This makes them highly desirable for industries that deal with corrosive substances such as acids, salts, and chlorides. These flanges have been known to outperform even the most corrosion-resistant alloys when exposed to aggressive media.

Product Specifications

Parameter	Details
Material Grade	F51 (UNS S31803; EN 1.4462), Duplex Stainless Steel with 21-23% Chromium, 4.5-6.5% Nickel, 2.5-3.5% Molybdenum, 0.08-0.20% Nitrogen
Mechanical Properties	Tensile Strength ≥620MPa, Yield Strength ≥450MPa, Elongation ≥25%, Hardness ≤290 HB
Nominal Diameter	Standard Sizes from DN10 (3/8") to DN2000 (80"), Custom Sizes Available
Pressure Rating	Class 150-2500 (lb); PN16-PN100, Suitable for Medium to High Pressure Piping Systems
Compliance Standards	Material: ASTM A182/A182M; Dimensions: ASME B16.5, ASME B16.47, EN 1092-1, etc.
Inspection Standards	Complies with ASTM E165 (Liquid Penetrant Testing), ASTM E709 (Magnetic Particle Testing), and ASME BPVC Section VIII

Processing Services

Service Type	Details
Custom Cutting	Cut to Specific Dimensions with Precision of ±0.5mm
Flange Forming	Available in Various Types: Slip-On, Weld Neck, Socket Weld, Threaded, etc.
Surface Treatment	Pickling Passivation, Polishing (Ra≤0.8μm), Sandblasting, etc. to Enhance Corrosion Resistance
Welding Service	TIG Welding Process Ensures Mechanical Properties of Weld Joints Match Base Material
Non-Destructive Testing	Post-Processing Inspections: Ultrasonic Testing (UT), Radiographic Testing (RT), etc.
Identification Marking	Laser Engraving for Specifications, Material Grade, Standards, etc. for Traceability

Common Standards for Duplex Stainless Steel Flanges

ASTM A182: Standard for forged or rolled alloy and stainless steel pipe flanges, forged fittings, and valves and parts for high-temperature service.

ASTM A240: Standard for chromium and chromium-nickel stainless steel plates, sheets, and strips for pressure vessels and general applications.

ASME B16.5: Standard for pipe flanges and flanged fittings, covering sizes NPS ½ to NPS 24.

ASME B16.47: Large diameter steel flanges, NPS 26 through NPS 60.

EN 1092-1: European standard for flanges.

API 605: Standard for large-diameter carbon steel flanges (similar to ASME B16.47).

Duplex Stainless Steel Grades

UNS S31803 (1.4462)

Known as Duplex 2205, it’s one of the most commonly used duplex grades. Offers good pitting and crevice corrosion resistance, with a balanced austenite and ferrite structure.

UNS S32205 (1.4462)

Similar to S31803 but with slightly improved corrosion resistance, particularly in chloride-containing environments.

UNS S32750 (1.4410)

Super duplex stainless steel with a higher alloy content, offering better corrosion resistance and mechanical properties. Known as SAF 2507.

UNS S32760 (1.4501)

Another super duplex grade with even higher corrosion resistance, used in highly aggressive environments such as offshore and chemical processing.

Mechanical Properties

Duplex stainless steel generally has higher tensile strength and yield strength than standard austenitic grades like 316L. The typical yield strength of duplex stainless steel is in the range of 450-550 MPa, and tensile strength can reach up to 700-800 MPa.

Specifications

Temperature Range: Duplex stainless steel flanges are suitable for use in environments ranging from cryogenic temperatures to about 300°C.

Corrosion Resistance: The duplex microstructure provides excellent resistance to chloride stress corrosion cracking, pitting, and crevice corrosion. Super duplex grades are particularly suited for highly corrosive environments.

Pressure Rating: Depending on the standard and class (such as ASME B16.5 Class 150, 300, 600, etc.), duplex flanges can withstand high pressures.

Common Types of Duplex Stainless Steel Flanges We Offer

Flange Type	Description
Weld Neck Flange	Designed for high-pressure systems; offers excellent stress distribution and leak-proof connections.
Slip-On Flange	Easy to install; used in low-pressure applications where welding on both sides is preferred.
Blind Flange	Used to terminate pipelines or vessels; ideal for pressure testing and system isolation.
Socket Weld Flange	Suitable for small-diameter, high-pressure pipelines; ensures smooth bore and good flow.
Lap Joint Flange	Used with stub ends; ideal for systems that require frequent dismantling or inspection.
Threaded Flange	Enables bolt-on connections without welding; used in low-pressure, non-critical piping.
Ring-Type Joint (RTJ)	Designed for high-pressure, high-temperature services; ensures a strong metal-to-metal seal.
Orifice Flange	Integrated with pressure tap holes; used with orifice meters to measure flow rate.

Key Industries Using Duplex Steel Flanges

Industry	Application Use
Oil & Gas	Subsea pipelines, FPSO units, wellheads, pressure vessels
Petrochemical & Refining	Reactor lines, heat exchangers, high-temperature & corrosive processing loops
Water & Wastewater Treatment	Desalination plants, filtration skids, chlorinated systems
Marine & Offshore	Ballast systems, riser pipelines, shipbuilding, underwater assemblies
Pulp & Paper	Bleach plants, chemical recovery units, digesters
Power Generation	Heat recovery steam generators (HRSG), condensate systems
Pharmaceutical & Food	Sanitary systems exposed to cleaning agents and moderate chlorides

Our Certificate

FAQ

Q: What product information do I need to provide?

A: You need to provide the grade, width, thickness, coating and the number of tons you need to purchase.

Q: How long will it take to execute my order?

A: Delivery time of stock products: 3-7 days after payment. Custom product delivery time: 20-45 days after payment.

Q: Can I have a sample for testing?

A: The cost of the samples is according to the value. The cost of the freight is necessary.

Q: Do you have inspection for the products before packing?

A: All products have to go through three checks in the whole manufacturing process,it includes production and Random Testing in warehouse and Before Shipping.and accept the third party inspection .

Q: Can I get your best price?

A: Price is different based on steel grade, size and quantity.Our goal is to provide you the best price with great quality assured in a long run.Please leave your contact information for the includes production.we will get back to you with the best solutions as soon as we can.Please give those info, for price checking.If the required is sheet metal fabrication, please send drawing.

Q: How to order?

A: Buyer sends the inquiry --> Buyer gets the quotation-->Order confirmation-->Buyer send the deposit-->Seller prepares

As one of the leading duplex stainless steel flange manufacturers and suppliers in China, we warmly welcome you to buy high quality duplex stainless steel flange for sale here from our factory. Good service and reasonable price are available.