At XTD, the available OD ranges from 6 mm to 720 mm. Wall thickness is 1 mm to 65 mm. Standard lengths are up to 22 m.
Super Duplex Steel Seamless Tube Manufacturer in China
We provide premium Super duplex stainless steel seamless (SMLS) tubes at Zhejiang Xintongda Special Steel (XTD). This specialized tubing, also known as SDSS seamless tubes, is known for its continuous, solid metal structure. It is manufactured without any longitudinal or circumferential welded seams. We manufacture this SMLS tube in compliance with the ASTM A789 standard. By prioritising a completely seamless construction, the tube achieves superior structural integrity. This ensures uniform mechanical properties and consistent thickness throughout the tube. The manufacturing process involves heating, piercing, and precise finishing to transform solid billets into hollow sections. The absence of welds makes it perfect for high-pressure systems where joint failure is not an option. We have multiple international certifications and an annual supply capacity of 25,000 tons. We offer super duplex seamless tubes in a range of grades, such as UNS S32750, UNS S32760, and UNS S32550, which are explained in a further section.
Our tubes meet the following specifications:
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OD Range 6-720 mm -
Thickness1-65 mm -
Length ≤ 22 m
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What is a Super Duplex Steel Seamless Tube?
A Super duplex steel seamless tube is a hollow section designed for moving fluids under extreme pressure and heat. It endures harsh chemical environments and deep-sea conditions. The seamless construction means the tube is made from a single piece of metal without any joined edges. This ensures the structure is perfectly uniform and lacks the weak points found in welded alternatives.
Manufacturing Process of Super Duplex Steel Seamless Tubes
The production process begins by heating a solid round billet and piercing the centre to create a shell. To get the proper strength the hollow shell goes through cold working and a final heat treatment. This makes sure that the metal's grain structure stays consistent. To learn more about our detailed seamless tube manufacturing process, refer to this page.
Super Duplex Grades Commonly Supplied as Seamless Tubes
We provide Super duplex grades, such as UNS S32750, UNS S32760, and UNS S32550 at XTD for use in demanding applications:
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UNS S32750 Seamless Tube
UNS S32750 tube consists of 24–26% chromium, 6–8% nickel, 3–5% molybdenum, and 0.24–0.32% nitrogen. It has a PREN value of ≥ 41 and offers incredible resistance to pitting and stress corrosion cracking in very harsh environments. This makes it a highly preferred choice for saltwater applications and chemical processing plants.
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UNS S32760 Seamless Tube
UNS S32760 tube has 24-26% chromium, 6-8% nickel, 3-4% molybdenum, and equal additions of tungsten and copper (0.5-1%) for improved stability in acidic media. It has a PREN of ≥ 41. It is frequently used in oil and gas extraction due to its high mechanical strength.
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UNS S32550 Seamless Tube
UNS S32550 tube consists of 24-27% chromium, 4.5-6.5% nickel, 3-4% molybdenum, and 1.5-2.5% of copper. It provides excellent durability and resistance to abrasion or erosion. It performs exceptionally well in marine engineering and heavy industrial scrubbers due to its PREN value of ≥ 38.
100% Certified Testing & Documentation
- Raw Materials Certificate
- 100% Positive Material Identification (PMI)
- Heat Treatment Charts
- Third-Party Inspection Report
- Surface roughness and size measurement
- Manufacturer Test Certificate (Impact Testing, Flattening, Flare, Bend, Hardness, Intergranular Corrosion, Pitting Corrosion, Grain size, Eddy Current (ET), Ultrasonic Testing (UT), Hydrostatic Testing (HT), etc.)
- Laboratory Test Certificate from Govt. Approved Lab
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Frequently Asked Questions
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What are the available OD, wall thickness (schedule), and standard lengths?
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Why choose Seamless Super Duplex Steel Tube over welded tubes?You should choose seamless Super duplex steel tube over welded tubes because seamless tubes have no weld seams, so they offer better strength and corrosion resistance in high-pressure applications. Welded tubes risk seam weaknesses under stress.
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Which industries use Super Duplex Steel Seamless Tubes?Industries that use Super duplex steel seamless tubes include oil and gas, chemical processing, marine, power generation, and desalination. They handle harsh, corrosive environments well.
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What are the main benefits of Super Duplex Steel SMLS Tubes?The main benefits of Super duplex steel SMLS tubes include high strength and excellent pitting/crevice corrosion resistance. This makes it ideal for extreme temperatures and pressures.
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Which super duplex grades do you supply?We supply Super duplex grades like UNS S32750 (2507), S32760 (Zeron 100) and S32550 (Ferralium 255).
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Which product standards do you manufacture to (e.g., ASTM A789 / A790)?We manufacture these tubes at XTD to the ASTM A789 standard.
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What is the current stock availability versus lead time for made-to-order production?To know about our stock availability, refer to our live stock page. The lead time for made-to-order production orders is 15-60 days.