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Utilizing 26 high-precision cold rolling mills and 6 cold drawing machines, we ensure dimensional accuracy and superior mechanical properties.
Sour Service S31803 Duplex Steel Tube
2205 Duplex | UNS S31803 | NACE MR0175 / ISO 15156 Compliant
Hardness ≤ 28 HRC | Sour Service | ASME SA790Related Products
Introduction
Sour Service S31803 Duplex Steel Tube addresses wet hydrogen sulfide (H2S) environments, where hydrogen can enter the steel and cause sulfide stress cracking. Sour service is governed by NACE MR0175 / ISO 15156, which sets hardness ceilings and permitted environmental limits for each material class. For solution-annealed 2205 duplex the standard hardness limit is 28 HRC, and the standard restricts the combination of temperature, chloride content, H2S partial pressure and pH in which the material can be used, so the tube must be bought against a specific service window rather than a generic grade name.
Manufacturing controls therefore focus on what can raise hardness or damage the ferrite-austenite balance. Cold work, unannealed welds and secondary phases such as sigma all raise hardness and reduce cracking resistance, so tubes are fully solution annealed and rapidly quenched, hardness is tested on each lot and ferrite content is held within 35-55%. Cold-drawn or bent sections that exceed the hardness limit are re-annealed. Mill certificates report Rockwell or Vickers values with the test location, giving the purchaser evidence for a MR0175 compliance file.
Typical uses include gathering lines and flowlines carrying wet sour gas with chlorides, wellhead and christmas tree instrument tubing, separator and scrubber piping and produced-water handling on sour fields. Chloride stress corrosion and hydrogen embrittlement both remain risks at high temperature or high H2S partial pressure, so for severe sour wells engineers often step up to super duplex or nickel alloys such as 825 and 625. S31803 fits the moderate sour window where its strength and cost advantage over those alloys is meaningful.
Specifications
| Material Grade | S31803 (UNS S31803) |
| Standard | ASTM A790 + NACE MR0175 / ISO 15156 |
| Outer Diameter | 6.35mm - 219mm |
| Wall Thickness | 1.0mm - 20mm |
| Length | Up to 12000mm |
| Finish | Solution Annealed, Pickled |
Chemical Composition
| C | Cr | Ni | Mo | N |
| ≤.03 | 21-23 | 4.5-6.5 | 2.5-3.5 | .08-.20 |
Sour Service Hardness Controlled
Mechanical Strength
Comprehensive Info
| MOQ | 300kg |
| Lead Time | 35 - 50 Days |
| Testing | Hardness per Lot & Ferrite 35-55% |
| Compliance File | MR0175 Document on Request |
Key Applications
Sour Flowlines Wet sour gas gathering and flowlines
Wellhead Instrumentation Control and sampling tube on sour wells
Produced Water H2S-bearing produced-water systems
Advantages
MR0175 Documentation
Hardness and heat treatment records for compliance.
Hardness Limited
Each lot tested against the 28 HRC ceiling.
High Strength
450 MPa yield beats carbon steel plus inhibitor.
Below Nickel Alloy Cost
Cheaper than 825 and 625 in moderate sour service.
About Jiangsu Jend Tube Co.,Ltd.
As China Sour Service S31803 Duplex Steel Tube Manufacturers and Wholesale Sour Service S31803 Duplex Steel Tube Factory, Established in 2011 and is a manufacturing enterprise with a complete manufacturing cycle from raw material selection to finished product delivery. The company currently has more than 100 employees, covers an area of 30015 square meters, and has a registered capital of 48 million yuan, annual production capacity of 3800 tons.
The company has passed ISO9001:2015 quality certification, domestic pressure vessel TS certification, and foreign pressure vessel PED certification. With rich experience and mature technology, we have been expanding our market internationally. At present, our products are exported to more than 50 countries and regions including Europe, America, Southeast Asia, and the Middle East.
The company adheres to different production norms and standards such as the American standard (ASTM), the European standard (EN), the German standard (DIN), the Japanese standard (JIS), the Russian standard (GOST), and the Chinese standard (GB).
Our company specializes in and customizes various specifications of Martensite TP410 (0Cr13, 1Cr13), Ferrite TP405 (1Cr13Al), TP430 (1Cr17), TP444 (0Cr18Mo2), TP439, TP409 (0Cr11Ti), It is also proficient in manufacturing Austenitic seamless stainless steel pipes of series such as TP304(L/H), TP316(L/H/Ti), TP310S, TP317, TP321(H) and TP347(H). Duplex such as S31803, S2205, S32750, S32304, and Nickel-based alloys Monel400, Monel600, Monel800, GH3030, 904L, Inconel 625, etc.
The company mainly produces seamless steel pipes with the following specifications: outer diameter: 3.18mm to 406.4mm, wall thickness: 0.3mm to 20mm, and the longest length is 25000mm. Additionally, it can customize seamless steel pipes with special materials and specifications according to customer requirements. The company attaches great importance to scientific innovation. The staff of the company vigorously develop technological research and development.
Jiangsu Jend Tube Co.,Ltd. will continuously accumulate professional knowledge and capabilities, striving to become a leader in the domestic market and even the world market. Strive to be the most reassuring pipe manufacturing enterprise for customers.
Precision Manufacturing and Process Optimization
We rely on precision equipment and optimized production technologies to achieve outstanding mechanical performance and consistent product quality.
Cold Rolling and Cold Drawing
Solution Heat Treatment
Natural gas solution treatment furnaces and BA solution treatment furnaces optimize the material's grain structure, enhancing corrosion resistance.
Precision Straightening and Polishing
10 straightening machines and 8 finishing polishing machines guarantee product surface smoothness and dimensional accuracy.
Automated Inspection and Quality Assurance
Real-time monitoring systems ensure the stable quality of every batch of products.
Usage Tips
Define the Service Window
Give us H2S partial pressure, chloride, pH and temperature; MR0175 limits depend on all four.
Watch Cold Work
Bent or cold-drawn sections can exceed 28 HRC and must be re-annealed before sour service.
Services
Hardness Testing
Rockwell or Vickers per lot with report.
Re-Annealing
Solution treatment for bent or drawn parts.
Compliance Package
Heat treatment and test records assembled.
Logistics
30% T/T Deposit / L/C at sight. Ends capped, tube sleeved and packed in export wooden cases with heat number tags visible on every bundle.
Standards
ASTM A790
NACE MR0175 / ISO 15156
API 5LC (on request)
ISO 9001
Frequently Asked Questions
What hardness limit applies to 2205 in sour service?
Solution-annealed duplex 2205 is generally limited to 28 HRC under NACE MR0175 / ISO 15156, with additional environmental limits.
Can S31803 be used at any H2S level?
No, permitted H2S partial pressure, temperature, chloride and pH are limited in the standard.
What is sulfide stress cracking?
Cracking of hard or stressed metal in the presence of hydrogen sulfide and water.
Why control ferrite content?
Too little or too much ferrite lowers cracking resistance and toughness.
What if the service is more severe?
Super duplex or nickel alloys are usually recommended above the S31803 window.
Do you supply hardness reports?
Yes, with the test location noted on the certificate.
Sour Service Tube Requirement?
Send H2S partial pressure, chloride, pH and temperature for a material and compliance recommendation.
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