Super Duplex Stainless Steel Flanges and Fittings

Super Duplex Stainless Steel Flanges and Fittings

The high chromium and molybdenum content of super duplex stainless steel flanges and fittings or UNS S32750/S32760 makes it extremely resistant to uniform corrosion by organic acids like formic and acetic acid. UNS S32750 Super Duplex Fittings and Flange also provide excellent resistance to inorganic acids, especially those containing chlorides.

Chemical composition

S32750/S3260 min 24 0.5 3 0.24 6
max 26 0.03 1 2 5 0.35 8 0.35 0.03 1

Super duplex steel flanges S32750/S32760 have high thermal conductivity as compared to other austenitic stainless steel. Super duplex flanges have high mechanical strength and good ductility with excellent corrosion resistance in a variety of environments. 

Mechanical Properties

Grade Tensile Strength Yield Strength Elongation Reduction of area
[MPA] [MPA] (% in 50mm) min min %
S32750 900 550 15
S32760 750-895 550 25 45

Super duplex pipe fittings and super duplex tube fittings S32750/S32760 often perform well in environments which cause premature failure of austenitic grades and super duplex fittings have better resistance to seawater than Grade 316. 

Physical properties

Grade Density (g/cm3) Melting Range °C Elastic Modulus (GPa) Thermal Expansion coefficient (μm/m/°C) Thermal Conductivity (W/m.K) Specific Heat (J/Kg.K) Electrical Resistivity (μΩ.cm)
S32750/S32760 7.8 1350°C / 2460°F 200 11.1 14.2 475 8.5

Specification of Flange 

The specified ASTM Standard Specification for Wrought Ferritic- Austenitic super duplex stainless steel flanges is ASTM A182 with manufacturing standard such as ANSI/ASME B16.5, B16.48, BS4504, B 16.47 Series A & B, BS 10, EN-1092, DIN, etc.

According to application and uses in pipes and tubes Duplex  S32750/S32760  flanges are broadly grouped into different sort, for example,  Welding Neck Flange(WNF) & Long Welding Neck Flange(LWNF), Slip-on Flange(SOF), Lap Joint Flange(LJW), Blind Flange, Socket Welding Flange (SWF), Threaded Flange(THW), Plate Flange.

SS Super Duplex Flange for the most part has different  face type, for example, Flat Face (FF), Raised Face (RF), Ring Type Joint (RTJ), blind flange, with various class rating as 50 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS, DIN Standard ND-6,10, 16,din 2.4856 , 25, 40 & ANSI B16.5.

Specification of Fittings

The Specification for Wrought Ferritic- Austenitic super duplex pipe fittings is ASTM A 815, having Specific manufacturing Standards as ASME/ANSI B16.9, ASME B16.28, MSS-SP-43. 

SS Super Duplex grade Fittings are categorically available are Elbow, Reducer, Tee, Coupling, Bend, Stub End, Cap, Nipple, Washer, Cross, Union etc which are available in different  types such as Welded, Seamless and Fabricated having thickness range from 5s, 10s, 40s, 80s, 10, 20, 40, STD, 60, 80, XS, 100, 120, 140, 160, XXS available with NACE MR 01-75


Super duplex S32750/S32760 flanges and fittings are often used in desalination plants, seawater piping and high pressure RO plants, structural and mechanical components. Super duplex S32750/S32760 flanges and fittings are also used in Oil and Gas industry equipment, Heat exchangers, offshore platforms, process and service water systems.