Duplex Steel Flanges

Duplex Stainless Steel Flanges

Duplex Stainless Steel Flanges

Duplex Steel Flanges are used in connecting pipes and fittings together. Flanges are piping components which are used to connect parts together with raised collars, faces or surfaces to allow better connection with welding or bolting. Naman Pipe & Tubes is a manufacturer and supplier of different types, grades, sizes and shapes of duplex steel flanges. Our Duplex Flanges are used in many industries like the natural oil and gas industries, petroleum refineries, sea water applications, waste water management plants, heaters and boilers and so on.

The advantage of Duplex Stainless Steel Flanges over ordinary stainless steel flanges is that they are very strong and are much corrosion resistant. The prices may slightly be higher than that of the ordinary steel products but our duplex steel flanges are cost efficient in the long run because they have a long lasting lifespan. The Duplex Blind Flange is one of the most used types that are used to close a connection with a blind at the end of a pipe. The SS Duplex Weld Neck Flanges manufactured by us make the welding and sealing much easier and stronger due to the welded neck at each flange. Please contact us for any Duplex Steel Slip On Flanges or any other types.

Duplex Steel Flanges Sizes


1/2" (15 NB) to 48" (1200NB)


Class 150 to 2500 LBS

DIN Pressure Rating

6Bar to 40Bar / PN6 to PN64


5K, 10 K, 16 K 20 K, 30 K, 40 K, 63 K

DSS Pipe Flanges Specifications

Specifications ASTM A182 / ASME SA 182
ANSI/ ASA / ASME B16.5, B 16.47 Series A & B, B16.48, BS 10, DIN, JIS, BS4504, EN-1092
Flange Face Raised Face (RF), Ring Type Joint (RTJ), Large Male-Female (LMF), Flat Face (FF), Small Male-Female (SMF), Lap-Joint Face (LJF), Small Tongue, Large Tongue & Groove, Groove
Material Grade A182 Grade F51 / F52 / F53 / F54 / F55 / F57 / F59 / F60 / F61

Different Types of Duplex Stainless Steel Flanges

Duplex Steel Flanges Types
Duplex Steel Flanges

Duplex Steel Flanges

  • Weld Neck Ring Flanges (WNRF)
  • Slip-On Ring Flanges (SORF)
  • Blind Ring Flanges (BLRF)
Duplex Stainless Steel Forged Flanges

Duplex Stainless Steel Forged Flanges

  • Socket Weld Ring Flanges (SWRF)
  • Threaded Ring Flanges
  • Lap Joint Ring Flanges

DSS Forged Flanges Price in India

Type Price/ piece
DSS Slip On Flanges (SO FLANGE) 3mm INR 12,275 / piece
DSS Slip On Flanges (SO FLANGE) 1.5mm INR 7,704 / piece
4 #600 SORF WITH HUB INR 13,738 / piece
1-1/2 #600 SORF WITH HUB INR 1,982 / piece

How to do duplex stainless steel flange pressure rating calculation?

The pressure ratings are specific to each type of material, temperature and class or specification. The pressure ratings come in different classes, namely the 150, 300, 400, 600, 900, 1500 and 2500. These depend primarily on the material such as 304, 316 in stainless steels and then the alloys such as cupronickel, nickel chromium. The duplex is a mixture of austenitic and ferritic steel structures. The material’s pressure rating depends on the operating temperature as well. As the temperature increases, the pressure capacities decrease. The pressure rating calculations should be taken from charts that are provided for each material in accordance to different temperatures.

Chemical Composition of UNS S31803 / S32205 Flanges

SS 2205 C Mn Si P S Cr Mo Ni N Fe
S31803 00.030 max 2.00 max 1.00 max 00.030 max 00.020 max 22.0 - 23.0 3.0 - 3.5 4.50 - 6.50 00.14 - 00.20 63.72 min
S32205 00.030 max 2.00 max 1.00 max 00.030 max 00.020 max 21.0 - 23.0 2.50 - 3.50 4.50 - 6.50 00.8 - 00.20 63.54 min

Mechanical Properties of UNS S31803 / S32205 Pipe Flanges

DSS 2205 Density Melting Range
UNS S31803 / S32205 7.805 g/cm 3
0.285 lb/in 3
1420 - 1465 °C
2588 - 2669 °F

UNS S31803 / S32205 Alloy 2205 Flanges Equivalent Grades

SS 2205 1.4462 S31803 ASTM A182 SA 182
SS 2205 1.4462 S32205 ASTM A182 SA 182