Oil and gas, chemical processing, offshore platforms, desalination plants, and marine industries use Super duplex steel seamless pipes for corrosion resistance in harsh environments.
Super Duplex Steel Seamless Pipes Manufacturer in China
We are Zhejiang Xintongda Special Steel (XTD), a renowned Super duplex steel seamless pipe manufacturer and supplier. This pipe is a high-strength, corrosion-resistant conduit manufactured entirely without a welded longitudinal seam. We manufacture this pipe in compliance with the ASTM A790 standard. The seamless construction eliminates the inherent structural vulnerabilities associated with welded joints. This results in a pipe that offers superior pressure containment and chemical stability. This manufacturing process involves transforming a solid cylindrical billet into a hollow shell through high-temperature piercing and cold finishing. This method makes our pipe the ideal choice for high-pressure subsea applications and aggressive chemical processing where total material integrity is non-negotiable. The production process ensures a homogenous grain structure throughout the wall thickness. This enhances the longevity of the system. We provide Super duplex pipes in different grades to meet diverse project requirements, which we explain below. We are ISO-certified and have an annual supply capacity of 25,000 tons. Our 4 decades of experience make us a reputable supplier of Super duplex steel pipes in seamless form.
We manufacture pipes that meet the following specifications:
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OD Range
6-720 mm
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Thickness
1-65 mm
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Length
≤ 18 m
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What is a Super Duplex Steel Seamless Pipe?
A Super duplex steel seamless pipe is a high-strength, corrosion-resistant, and high-performance tubular product. It is made from a 50% ferrite and 50% austenite structure. The seamless construction means it is made from a single piece of solid steel that creates a consistent metallurgical structure across the entire circumference. It is designed for harsh environments and consists of high levels of chromium, molybdenum and nickel. It consists of 3 grades, namely UNS S32750, UNS S32760, and UNS S32250, that offer superior resistance to pitting and stress corrosion cracking in oil & gas and chemical processing industries.
Manufacturing Process of SDSS Seamless Pipes
The production process of SDSS seamless pipes begins by heating a solid steel billet and piercing it to create a hollow shell. After that, the shell is cold worked and heated to the right temperature to get the right mechanical properties. This process ensures that the finished pipe has a smooth surface and a fine internal grain structure. For details on our manufacturing process, refer to our production page.
Super Duplex Grades Commonly Delivered as Seamless Pipes
We offer the following 3 Super duplex grades, like UNS S32750, UNS S32550, and UNS S3276,0 as seamless pipes at XTD:
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UNS S32750 Seamless Pipe
UNS S32750 Pipe consists of 24–26% chromium, 6–8% nickel, 3–5% molybdenum, and 0.24–0.32% nitrogen. It has a PREN value of ≥ 41. It is the most common super duplex variety, known for its high alloy content and exceptional strength. It provides excellent resistance to chloride stress corrosion cracking in seawater applications.
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UNS S32550 Seamless Pipe
UNS S32550 pipe consists of 24-27% chromium, 4.5-6.5% nickel, 3-4% molybdenum, and 1.5-2.5% of copper. The high copper content significantly improves its resistance to sulfuric acid. It has a PREN value of ≥ 38. It is frequently selected for its durability in rugged chemical processing and marine engineering environments.
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UNS S32760 Seamless Pipe
UNS S32760 pipe has 24-26% chromium, 6-8% nickel, 3-4% molybdenum, and equal additions of tungsten and copper (0.5-1%) to enhance performance in sour gas environments. It has a PREN of ≥ 41. It is a reliable choice for deep-sea oil and gas exploration where stability is vital.
100% Certified Testing & Documentation
- Surface roughness and size measurement
- Laboratory Test Certificate from the Government-Approved Lab
- Raw Materials Certificate
- 100% PMI
- Heat Treatment Charts
- EN 10204 3.1 and EN 10204 3.2 Material Test Certificates (MTC)
- Third-Party Inspection Report
- Manufacturer Test Certificate (Impact Testing, Flattening, Flare, Bend, Hardness, Intergranular, Pitting Corrosion, Grain size, ET, UT, HT...)
Frequently Asked Questions
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Which industries use Super Duplex Steel Seamless Pipes?
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What are the available OD, wall thickness (schedule), and standard lengths?At XTD we provide Super duplex steel pipes in OD ranges from 6 mm to 720 mm. Thickness ranges between 1 mm and 65 mm and standard lengths are up to 18 m.
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Which product standards do you manufacture to (e.g., ASTM A789 / A790)?We manufacture this pipe to the ASTM A790 standard at XTD.
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What are the main benefits of Super Duplex Steel SMLS Pipes?The main benefits of Super duplex steel SMLS pipes are high strength, excellent pitting/crevice corrosion resistance, superior stress corrosion cracking resistance, and durability in chloride/acid environments.
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What is the current stock availability versus lead time for made-to-order production?Check our live stock page to learn about our current stock availability. The lead time for our made-to-order production is 15 to 60 days.
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Why choose Seamless Super Duplex Steel Pipe over welded Pipes?The reason you should choose seamless Super duplex steel pipe over welded pipes is that seamless pipe offers higher pressure ratings, no weld seams for better corrosion resistance, and superior strength uniformity.
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Which Super duplex grades do you supply?We supply Super duplex grades UNS S32750, UNS S32550, and UNS S32760 at XTD.