Metinox Overseas manufactures and supplies super duplex stainless steel UNS S32750 pipes and tubes, the 2507 grade, to projects across the USA, the Middle East and Africa in ASTM A790 pipe and A789 tube, seamless and welded. S32750 is the widely stocked super duplex, with a pitting resistance number above 40 that makes it a seawater and high-chloride grade, and it is the default 2507 specification for most super duplex work. This page sits within our duplex steel pipes range, and the tungsten-bearing alternative is on our super duplex S32760 pipes page.
Super duplex combines about twice the strength of standard austenitic stainless with the corrosion resistance seawater, chlorinated cooling and acid service demand. We supply S32750 as pipe for pressure lines and as super duplex S32750 tubes for heat-exchanger and instrument service, from half an inch to 24 inch and above, with ferrite balance and PREN confirmed on the certificate. Send the form, size and quantity and the quote comes back with the mill certificates and regional approvals your project requires.
Table of Contents
- Super Duplex Stainless Steel S32750 Pipe Specification
- ASME SA790 Super Duplex Steel S32750 Pipes Chemical Composition
- UNS S32750 Super Duplex Stainless Steel Seamless and Welded Pipe Mechanical Properties
- ASTM A790 Super Duplex Steel S32750 Pipes Equivalent Grades
- Manufacturing Processes of Super Duplex Stainless Steel UNS S32750 Pipes
- Applications of Super Duplex Stainless Steel UNS S32750 Pipes
- Advantages of Super Duplex Stainless Steel UNS S32750 Pipes
- Inspection & Test Reports of Super Duplex 2507 Pipe
- Why S32750: Strength & PREN Above 40
- S32750 vs S32760: Which Grade Do You Need?
- Pipe or Tube?
- Applications Across the USA, Middle East & Africa
- Quality, Testing & Certification
- Frequently Asked Questions (FAQ)
Super Duplex Stainless Steel S32750 Pipe Specification
| Property | Value |
|---|---|
| Grade | UNS S32750, 2507, W. Nr. 1.4410 |
| Type | Super duplex, 25Cr-7Ni-4Mo-N |
| PREN | 40 minimum (typically 41 or above) |
| Specifications | ASTM A790 (pipe), A789 (tube), A182 F53 for fittings/flanges |
| Forms | Seamless and welded pipe and tube |
| Size range | NPS ½ inch to 24 inch and above; tube to order |
| Certification | EN 10204 3.1 mill test certificate, ferrite & PREN, PMI, NACE MR0175 |
Manufacturing Processes of Super Duplex Stainless Steel UNS S32750 Pipes
Super Duplex Stainless Steel UNS S32750 pipes are manufactured under rigorous quality control in order to achieve outstanding strength, resistance to corrosion, and operation in severe conditions. All the production stages are strictly controlled to ensure a balanced austenitic-ferritic structure of the alloy and uniform mechanical characteristics.
Seamless Pipe Manufacturing:It starts with the selection of Super Duplex stainless steel billets of a controlled chemical composition of high quality. The billets are heated and rotary pierced as a uniform hollow shell. The shell is then hot rolled and cold finished to give specific dimensions, good surface finish and mechanical strength.
ERW / EFW Pipe Welding:In case of welded pipes, flat Super Duplex stainless steel plates or coils are shaped to the cylindrical shape and welded by either Electric Resistance Welding (ERW) or Electric Fusion Welding (EFW). The weld joint is well regulated so that the strength and corrosion resistance is uniform as the base material.
Heat Treatment/ Solution Annealing:The formation/welding is followed by solution annealing to restore the optimum microstructure. The process eliminates internal stresses, enhances toughness and offers maximum resistance against corrosion, especially in environments that have chloride presence.
Testing & Quality Control
The pipes are thoroughly tested, such as chemical analysis, mechanical testing, non-destructive tests, and hydrostatic tests. Such tests make sure that everything meets the global requirements and guarantee that products perform in the most critical situations.
Applications of Super Duplex Stainless Steel UNS S32750 Pipes
Super Duplex Stainless Steel UNS S32750 pipes are commonly used in many different industries, and some of the common ones are listed below.
Oil & Gas (Onshore & Offshore)
Widely used in pipelines, risers, and subsea lines where high pressure, chloride exposure, and corrosive environments demand superior stability.
Petrochemical & Chemical Processing
Ideal for reactors, heat exchangers, and piping systems handling aggressive chemicals at elevated temperatures.
Marine & Seawater Systems
Offers excellent resistance to seawater corrosion, making it suitable for ships, offshore platforms, and marine structures.
Desalination & Water Treatment
Commonly used in desalination plants, evaporators, and RO systems due to its strong resistance to saline and brackish water.
Heat Exchangers & Pressure Vessels
Preferred where high mechanical strength and corrosion resistance are critical in heat transfer and pressure equipment.
Advantages of Super Duplex Stainless Steel UNS S32750 Pipes
The advantages associated with Super Duplex Stainless Steel UNS S32750 pipes are the following that would render them viable in the challenging industrial conditions.
Strong to weight Ratio: Gives much greater strength than traditional stainless steels, giving the opportunity to use thinner walls and lower weight of the material.
Chloride Stress Corrosion Cracking Resistance: Performs well in chloride environments and high temperature where other stainless steels would not perform.
Excellent Pitting Insights and Crevice Resistance: Exceptional corrosion resistance to localized corrosion is assured by high levels of chromium and molybdenum and nitrogen.
Prolonged Performance: Provides a long life cycle with less maintenance, thereby leading to cost efficiency and reliability.
Inspection & Test Reports of Super Duplex 2507 Pipe
All our products go through a strict testing and quality control check process that helps us to provide the best quality product to our customers, and some of the inspection and test results are listed below.
- Mill Test Certificates are provided with all Super Duplex 2507 pipes
- Material Test Certificates in accordance with EN 10204 3.1, 3.1B, and 3.2 standards
- Third-party inspection certification for Super Duplex pipes
- Mechanical test reports
- Chemical composition analysis reports
- Positive Material Identification (PMI) test reports
- Visual inspection records
- Destructive testing reports
- Test reports from NABL-accredited laboratories
- Raw material certification documents
- Non-destructive examination (NDE) reports
- 100% radiographic examination reports
- Fumigation certification
- HS code-based commercial invoice
- Heat treatment records and charts
- Surface roughness measurement reports
- Form A under the Generalized System of Preferences (GSP)
- Laboratory test certificates from government-approved laboratories
- Moisture testing reports
Why S32750: Strength & PREN Above 40
Super duplex is chosen on its pitting resistance equivalent number, and S32750 carries a minimum PREN of 40, from a 25 percent chromium, 4 percent molybdenum, nitrogen-bearing chemistry. A PREN above 40 is the threshold that qualifies a grade for seawater, so S32750 resists the pitting and crevice corrosion that attack standard stainless and even standard duplex in chloride service. Its duplex structure also gives roughly double the yield strength of 304 or 316, so a line can be built with thinner walls and less metal, which offsets part of the higher price per kilo and is a real advantage on large seawater and firewater systems.
S32750 vs S32760: Which Grade Do You Need?
Both are super duplex above PREN 40 and both handle seawater, so the choice usually follows what the specification names. S32750, 2507, is the widely stocked default, without tungsten or copper additions, and covers most super duplex seawater and chloride duty. S32760, Zeron 100, adds tungsten and copper for extra margin in reducing acids and fast-flowing seawater and is often the named grade on offshore and desalination projects. Where a spec calls out one grade, supply that grade; where it is open, S32750 is the economical and widely available choice, and our super duplex S32760 pipes page covers the alternative.
Pipe or Tube?
The two forms serve different parts of a plant. S32750 pipe carries process and seawater flow under pressure and is ordered to ASTM A790 by NPS and schedule. S32750 tube is made to closer dimensional tolerance for heat exchangers, condensers and instrument lines and is ordered to ASTM A789 by outside diameter and wall. We supply both, and the super duplex S32750 tubes and wider super duplex steel tubes pages carry the tube-specific sizes. Tell us whether it is a pressure line or an exchanger and we confirm the form.
Applications Across the USA, Middle East & Africa
S32750 goes into the seawater and high-chloride service common to these regions: seawater cooling, firewater and ballast systems, desalination plant across the Middle East and North Africa, oil and gas gathering and process, and chemical lines. Its strength-to-weight and corrosion margin suit the high-chloride, high-temperature conditions where standard stainless falls short. It pairs with our duplex & super duplex flanges and the wider special alloys pipes & tubes range, supplied with the approvals and documentation these regions require.
Quality, Testing & Certification
Super duplex depends on a correct ferrite-austenite balance, so every S32750 pipe and tube carries an EN 10204 3.1 mill test certificate with ferrite content and PREN reported, heat-number traceable, because an incorrect phase balance undermines both the strength and the corrosion resistance the grade is bought for. Positive material identification confirms the grade, and NACE MR0175 documentation for sour service and third-party witness through BV, SGS or TUV are arranged at order stage, in line with our quality policy. Product is marked and protected for export sea freight per our packing & dispatch standard. Send the form, size and quantity and the quote comes back with the certification built in.
Send Your Form, Size and Quantity →
Super Duplex S32750 Pipes & Tubes: Frequently Asked Questions
UNS S32750, known as 2507, is a super duplex stainless steel grade with a 25Cr-7Ni-4Mo-N chemistry and a minimum PREN of 40. Supplied as pipe to ASTM A790 and tube to A789 in seamless and welded form, it combines about twice the strength of standard austenitic stainless with the corrosion resistance seawater and chloride service demand. We supply it from half an inch to 24 inch and above.
Both are super duplex above PREN 40 and both handle seawater. S32750, 2507, is the widely stocked default without tungsten or copper additions. S32760, Zeron 100, adds tungsten and copper for extra margin in reducing acids and fast seawater and is often the named grade on offshore and desalination projects. Where a specification names one grade, supply that grade; for open specs S32750 is the economical, widely available choice.
Form and standard. S32750 pipe carries flow under pressure, is made to ASTM A790, and is ordered by NPS and schedule. S32750 tube is made to closer tolerance for heat exchangers, condensers and instrument lines, is made to ASTM A789, and is ordered by outside diameter and wall thickness. We supply both in the same 2507 grade.
S32750 has a minimum pitting resistance equivalent number of 40, typically 41 or above, from its chromium, molybdenum and nitrogen content. A PREN above 40 qualifies a grade as super duplex and suitable for seawater, which is why S32750 is used in desalination, seawater cooling and high-chloride service where lower grades would pit.
Yes. We manufacture and export S32750 super duplex pipe and tube to projects across the USA, the Middle East and Africa, with EN 10204 3.1 mill certificates reporting ferrite and PREN, positive material identification, NACE documentation and export packing for sea freight. The grade suits the seawater, desalination and sour service common to these regions.
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