duplex steel pipe, duplex steel tube, duplex ss pipe, duplex stainless steel pipe, duplex stainless steel tube, ss duplex pipe
duplex steel pipe, duplex steel tube, duplex ss pipe, duplex stainless steel pipe, duplex stainless steel tube, ss duplex pipe
duplex steel pipe, duplex steel tube, duplex ss pipe, duplex stainless steel pipe, duplex stainless steel tube, ss duplex pipe
duplex steel pipe, duplex steel tube, duplex ss pipe, duplex stainless steel pipe, duplex stainless steel tube, ss duplex pipe
Duplex Steel Pipes
Duplex Steel Pipes
Duplex Steel Pipes
Duplex Steel Pipes

Duplex Steel Pipes

Super Duplex Steel Pipe

Specifications

Pipe Types

Seamless Pipe, ERW Pipe, Welded Pipe, Fabricated Pipe, LSAW Pipe, Box Pipe.

Schedule

SCH5, SCH10, SCH20, SCH30, SCH40, STD, SCH80, XS, SCH60, SCH80, SCH120,SCH140, SCH160, XXS

Standard

ASME/ANSI B16.11, MSS-SP-97, MSS-SP-79, JIS B2316, BS 3799

Pipe Size

1/8"NB to 24"NB & 1/4"OD TO 24"OD AND 6.35mm to 254mm OD Thickness: 0.6mm to 20mm

Grades

Super Duplex Steel

ASTM/ASME A/SA 789, 790
- UNS NO S 31803, S 32205, S 32550, S 32750, S 32760.

  • Products details
  • Tolerance table
  • Chemical composition
  • Specification

Specifications

Super Duplex Steel Pipe

Specifications

Pipe Types

Seamless Pipe, ERW Pipe, Welded Pipe, Fabricated Pipe, LSAW Pipe, Box Pipe.

Schedule

SCH5, SCH10, SCH20, SCH30, SCH40, STD, SCH80, XS, SCH60, SCH80, SCH120,SCH140, SCH160, XXS

Standard

ASME/ANSI B16.11, MSS-SP-97, MSS-SP-79, JIS B2316, BS 3799

Pipe Size

1/8"NB to 24"NB & 1/4"OD TO 24"OD AND 6.35mm to 254mm OD Thickness: 0.6mm to 20mm

Grades

Super Duplex Steel

ASTM/ASME A/SA 789, 790
- UNS NO S 31803, S 32205, S 32550, S 32750, S 32760.

  • Process

Seamless pipes & tubes (Mannesmann process)


Electric resistance-welded pipes & tubes


  • Tests
Tension Test, Flattening Test, Hardness Test, or Bend Test; Hydrostatic Test or nondestructive electric test.
  • Packing & Delivery



Frequently Asked Questions

1. What is the difference between 2205 and 2507 duplex stainless pipes?

2205 (UNS S32205) contains 22% chromium, 3% molybdenum, 5-6% nickel. PREN: 22-23. Suitable for most corrosive environments.

2507 (UNS S32750) contains 25% chromium, 4% molybdenum, 7% nickel. PREN: >40. Superior chloride resistance, ideal for seawater and highly corrosive applications.

2507 costs 30-40% more than 2205. Selection depends on chloride concentration and temperature.

2. What are the key advantages of duplex stainless steel pipes?

Key advantages:

(1) Superior corrosion resistance - 2-3x better than 316L

(2) High strength - 2x yield strength of austenitic grades

(3) Cost-effective - Less nickel than austenitic grades

(4) Good weldability - No preheating typically required

(5) Excellent fatigue resistance

Ideal for: Oil & gas, petrochemical, marine, desalination, paper mills.

3. What is PREN and why is it important?

PREN (Pitting Resistance Equivalent Number) measures chloride pitting resistance:

PREN = %Cr + 3.3(%Mo) + 16(%N)

Guidelines:

- PREN >32: Excellent for seawater

- PREN >40: Superior chloride resistance

- 2205: PREN 22-23

- 2507: PREN >40

Higher PREN = better resistance to pitting and crevice corrosion in chloride environments.

4. What testing do you provide for duplex stainless pipes?

Testing included:

(1) PMI verification - Confirm chemical composition

(2) Intergranular corrosion test (ASTM A262 Practice E)

(3) Pitting corrosion test (ASTM G48)

(4) Hydrostatic test per ASTM A790

(5) Dimensional inspection

(6) Visual inspection

Mill Test Certificates (MTC) per EN 10204 3.1 provided.

5. What are the welding considerations for duplex pipes?

Welding requirements:

(1) Use matching filler metal (2209 for 2205, 2509 for 2507)

(2) Interpass temperature: <200°C for 2205, <100°C for 2507

(3) PWHT not required for most thicknesses

(4) Gas backing: Argon or Ar/He mix

(5) Post-weld pickling and passivation recommended

Our welders are certified to ASME Section IX.

6. What packaging ensures safe delivery of duplex pipes?

Standard packaging:

(1) PE caps on both ends - Prevent contamination

(2) Paper wrapping - Surface protection

(3) Steel straps - Secure bundling

(4) Wooden crates for polished surfaces

Loading: 20ft: 8-12 tons; 40ft: 18-22 tons.

FOB Tianjin/Qingdao available.

  • Tolerance table

Super Duplex Steel Pipe Dimensions Chart

NPS

Outside Diameter

Nominal Wall Thickness

Designator

in.

mm

Schedule 5S

Schedule 10S

Schedule 40S

Schedule 80S


in.

mm

in.

mm

in.

mm

in.

mm

1/8

0.41

10.29

-

-

0.049

1.24

0.068

1.73

0.095

2.41

1/4

0.54

13.72

-

-

0.065

1.65

0.088

2.24

0.119

3.02

3/8

0.68

17.15

-

-

0.065

1.65

0.091

2.31

0.126

3.2

1/2

0.84

21.34

0.065

1.65

0.083

2.11

0.109

2.77

0.147

3.73

3/4

4.05

26.67

0.065

1.65

0.083

2.11

0.113

2.87

0.154

3.91

1

1.32

33.4

0.065

1.65

0.109

2.77

0.133

3.38

0.179

4.55

1 1/4

1.66

42.16

0.065

1.65

0.109

2.77

0.14

3.56

0.191

4.85

1 1/2

1.90

48.26

0.065

1.65

0.109

2.77

0.145

3.68

0.2

5.08

2

2.38

60.33

0.065

1.65

0.109

2.77

0.154

3.91

0.218

5.54

2 1/2

2.88

73.03

0.083

2.11

0.12

3.05

0.203

5.16

0.276

7.01

3

3.50

88.9

0.083

2.11

0.12

3.05

0.1216

5.49

0.3

7.62

3 1/2

4.00

101.6

0.083

2.11

0.12

3.05

0.226

5.74

0.318

8.08

4

4.50

114.3

0.083

2.11

0.12

3.05

0.237

6.02

0.337

8.56

5

5.56

141.3

0.10*9

2.77

0.134

3.4

0.258

6.55

0.375

9.52

6

6.63

168.28

0.10*9

2.77

0.134

3.4

0.28

7.11

0.432

10.97

8

8.63

219.08

0.109

2.77

0.148

3.76

0.322

8.18

0.5

12.7

10

10.75

273.05

0.134

3.4

0.165

4.19

0.365

9.27

0.5

12.7

12

12.75

323.85

0.156

3.96

0.18

4.57

0.375

9.52

0.5

12.7

14

14.00

355.6

0.156

3.96

0.188

4.78

-

-

-

-

16

16.00

406.4

0.165

4.19

0.188

4.78

-

-

-

-

18

18.00

457.2

0.165

4.19

0.188

4.78

-

-

-

-

20

20.00

508

0.188

4.78

0.188

4.78

-

-

-

-

22

22.00

558.8

0.188

4.78

0.218

5.54

-

-

-

-

24

24.00

609.6

0.218

5.54

0.25

6.35

-

-

-

-

30

30.00

762

0.25

6.35

0.312

7.92

-

-

-

-

  • Chemical composition

Chemical Composition for Duplex Stainless Steel Pipe(%)


C

Mn

P

S

Si

Cr

Ni

Mo

N

Cu

UNS

S32101

0.03max

2.0max

0.03max

0.03max

1.0max

20.0~23.0

1.0~3.0

0.6max

0.05~0.17

1.0max

UNS

S31803

0.03max

2.0max

0.03max

0.02max

1.0max

21.0~23.0

4.5~6.5

2.5~3.5

0.08~0.20

/

UNS

S32205

0.03max

2.0max

0.03max

0.02max

1.0max

22.0~23.0

4.5~6.5

3.0~3.5

0.14~0.20

/

UNS

S32750

0.03max

1.2max

0.035max

0.02max

0.8max

24.0~26.0

6.0~8.0

3.0~5.0

0.24~0.32

0.5max

Duplex steel Pipe & Tube Mechanical Properties

Mechanical properties Tensile,min,ksi[MPa] Yield,min,ksi[MPa] Elongation,%(min) Hardness,HB(max)
S31803 90 [620] 65 [450] 25 290
S32205 95 [655] 65 [450] 25 290
S32750 116 [800] 80 [550] 15 300
S32760 109 [750] 80 [550] 25 300

Duplex Stainless steel pipes are manufactured according to the ASME B36.19 standard.
DUPLEX PIPE:S31803 Pipe, S32205 Pipe
SUPER DUPLEX PIPES:S32750 Pipe, S32760 Pipe
Duplex pipes and Super Duplex pipes match the following fittings materials: ASTM A815 (butt weld fittings) and ASTM A182 F51 / F53 / F55 / F60 (flanges / forged socket weld and threaded fittings).
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