As Senior Metal Products Manager at our specialized stainless steel and nickel alloy manufacturing facility, I oversee the production of high-performance Duplex Steel UNS S32750 Flanges. These components deliver the strength, corrosion resistance, and reliability required for the most demanding piping systems in oil & gas, petrochemical, chemical processing, desalination, and offshore platforms.
What Is Duplex Steel UNS S32750?
UNS S32750 (Super Duplex 2507 / ASTM A182 F53) is a 25Cr-7Ni-4Mo-0.28N super duplex stainless steel with a balanced 50/50 austenite-ferrite microstructure. Key properties include:
PREN value >40 for outstanding resistance to pitting and crevice corrosion
Excellent resistance to chloride stress corrosion cracking
Yield strength approximately twice that of standard austenitic grades
Good weldability and toughness down to –50 °C
Duplex Steel UNS S32750 Flanges Manufacturing Specifications and Standards
As a premier supplier, we align our production with the most stringent international standards. Whether you require standard-sized flanges or large-diameter structural components, our factory is equipped to deliver.
1. ASME B16.5 Compliance (NPS 1/2 to NPS 24)
For standard piping systems, we manufacture S32750 flanges according to ASME B16.5. This standard covers pressure-temperature ratings, materials, dimensions, tolerances, marking, and testing.
Pressure Classes: 150, 300, 400, 600, 900, 1500, and 2500.
Types: Weld Neck (WN), Slip-On (SO), Blind (BL), Threaded (TH), and Socket Weld (SW).
Face Types: Raised Face (RF), Flat Face (FF), and Ring Type Joint (RTJ).
2. ASME B16.47 Compliance (NPS 26 to NPS 60)
For large-scale infrastructure, such as pressure vessels or main transmission lines, we adhere to ASME B16.47. We offer both:
Series A (MSS SP-44): Generally thicker and heavier, used for more robust structural requirements.
Series B (API 605): More compact and lighter, often preferred for replacement work or space-constrained environments.
Duplex Steel UNS S32750 Flange Manufacturing Process
Our flanges are produced through a controlled, repeatable process that ensures consistent quality:
Forging: Hot forging from certified billets or ingots on hydraulic presses, followed by normalization to refine grain structure.
Heat Treatment: Solution annealing at 1020–1100°C with rapid water quenching to restore the duplex microstructure and maximize corrosion resistance.
Machining: CNC precision machining to achieve tight dimensional tolerances, smooth surface finishes (Ra ≤ 3.2 µm on gasket faces), and accurate bolt-hole alignment.
Finishing & Marking: Beveling, facing (raised face, ring-type joint, or flat face), and permanent stamping with heat number, material grade, size, class, and standard.
Available types include Weld Neck, Slip-On, Blind, Socket Weld, Threaded, Lap Joint, and Orifice Flanges. Surface treatments such as pickling, passivation, or electropolishing are offered upon request.
Quality Assurance and Authenticity
Our factory operates on the principle of transparency. Every shipment of UNS S32750 flanges is accompanied by a Material Test Report (MTR) in accordance with EN 10204 3.1 (or 3.2 upon request).
Our internal testing protocol includes:
Positive Material Identification (PMI): To verify chemical composition before and after production.
Ultrasonic Testing (UT): To ensure zero internal defects in the forged body.
Microstructure Analysis: To verify the phase balance and the absence of deleterious phases.
Corrosion Testing: ASTM G48 Method A test to verify pitting resistance.
Manager's Perspective: "In the metal industry, 'cheaper' often means 'risky.' A Super Duplex flange that has not been properly solution-annealed is a liability. We prioritize the thermal cycle to ensure our clients receive a product that is as ductile as it is strong."
Why Partner With Us?
As a specialist factory, we offer more than just a product; we offer engineering partnership. Our expertise in ASTM, ASME, BS, DIN, and GOST standards allows us to supply global projects with a single point of accountability.
Expertise: Decades of experience specifically in high-nickel and duplex alloys.
Rigorous Testing: Every flange is treated as a critical safety component.
Global Logistics: Efficient export capabilities ensuring your project stays on schedule.
The durability of your piping system is a reflection of the quality of its components. Choose the material that offers the highest yield and the supplier that offers the highest precision.
