Chemical Processing Coolers and Heaters
Coolers and heaters in chemical plants use this grade where process streams or cooling water carry chlorides, the kind of service ASTM A789 addresses with its stress corrosion cracking emphasis.
ASTM A789 / ASME SA-789 / UNS S32950
Super Duplex Steel UNS S32950 Seamless Tubes Manufacturer in Thailand
Thaida Stainless Steel Manufacturing (Thailand) Co., Ltd., working from Ban Bueng, Chonburi, Thailand, manufactures UNS S32950 super duplex steel seamless tubes to ASTM A789 for shell-and-tube coolers, condensers and process tubing that handle chloride-bearing streams. Within our super duplex steel seamless tubes range, S32950 has the highest chromium and the leanest nickel and molybdenum, and it is the only grade air cooled after heat treatment. Our commercial office sits in Bang Phli, Samut Prakan.
Super Duplex Steel UNS S32950 seamless tubeUNS S32950
- 6 to 720 mmOutside diameter
- 1 to 65 mmWall thickness
- Up to 22 mLength
- EN 10204 3.1Test certificate
EN 10204 3.1 certificate / 3.2 on request
ASME SA-789 S32950 Seamless Tube Specifications
Tube in this grade is specified by its OD and wall. The dimensions below are the range of our super duplex seamless tube production, and S32950 is made within it to the sizes on your order, with the wall held to whichever basis, average or minimum, you name.
- Standard
- ASTM A789 / ASME SA-789
- Grade
- UNS S32950
- Material Group
- Ferritic/austenitic (duplex) stainless steel, 26.0 to 29.0% Cr
- Outside Diameter
- 6 to 720 mm(super duplex seamless tube range)
- Wall Thickness
- 1 to 65 mmaverage or minimum wall
- Length
- Up to 22 mor cut to your drawing
- Form
- Seamlessround
- End Type
- Plain endbeveled end
- Manufacturing Route
- 1Solid round billet heated and pierced
- 2Cold worked
- 3Then heat treated
- Heat Treatment
- 990 °C to 1025 °C (1820 °F to 1880 °F), air cooled
- Surface
- Free of excessive mill scale, suitable for inspection
- Tolerances
- ASTM A789 Table 5, up to 203.2 mm OD
- Testing
- Hydrostatic or nondestructive electric test on every tube
- Tension, flaring and hardness tests per lot
- Test Certificate
- EN 10204 3.13.2 on request
ASTM A789 / ASME SA-789 is the governing specification, and every ASTM A789 UNS S32950 seamless tube we ship meets its chemistry, heat treatment and mechanical requirements. A789 was drafted for tubing in services that need general corrosion resistance and names stress corrosion cracking as its particular concern. Its scope clause adds that long exposure to elevated temperature can leave these steels brittle, so agree the tube metal temperature with your exchanger designer before ordering. Process lines sized by NPS and schedule in the same grade are produced as UNS S32950 seamless pipes to ASTM A790.
Each ASTM A789 UNS S32950 seamless tube is hydrostatically tested or given a nondestructive electric test; the method is ours to pick unless your order fixes it. In every lot, one tension test covers up to 50 tubes and two are taken above 50, a flaring test expands one tube end by at least 10% of its inside diameter, and two tubes are hardness tested. If one lot contains tubes from more than one heat, every heat gets its own set of these tests, and your order may also call for the optional S1 pneumatic examination, run as an air-underwater or leak test. All results appear on the EN 10204 3.1 (3.2 on request) certificate. Third-party inspection can also be arranged on request.
Chemical Composition of Seamless S32950 Super Duplex Steel Tube
ASTM A789 gives S32950 a higher chromium range than our other super duplex grades, 26.0 to 29.0%, together with nickel at 3.5 to 5.2% and molybdenum at 1.00 to 2.50%, and it sets no copper or tungsten requirement. Compared with UNS S32205 seamless tubes, the grade carries more chromium (22.0 to 23.0% for S32205) but less molybdenum (3.0 to 3.5% for S32205). The heat analysis of each seamless S32950 super duplex steel tube is checked against these limits:
- CrChromium, 26.0 to 29.0
- NiNickel, 3.5 to 5.2
- MoMolybdenum, 1.00 to 2.50
- MnManganese, 2.00 max
- SiSilicon, 0.60 max
UNS S32950S32950
| Element | Min. (%) | Max. (%) |
|---|---|---|
| C (Carbon) | - | 0.030 |
| Mn (Manganese) | - | 2.00 |
| P (Phosphorus) | - | 0.035 |
| S (Sulfur) | - | 0.010 |
| Si (Silicon) | - | 0.60 |
| Ni (Nickel) | 3.5 | 5.2 |
| Cr (Chromium) | 26.0 | 29.0 |
| Mo (Molybdenum) | 1.00 | 2.50 |
| N (Nitrogen) | 0.15 | 0.35 |
Super Duplex Steel S32950 Seamless Tube Mechanical Properties
Every super duplex steel S32950 seamless tube must meet the ASTM A789 limits below, and your design code turns them into allowable stresses. Apart from the Vickers limit, which appears only in the tube standard, the same figures govern the A790 pipe form.
| Requirement | ASTM A789, UNS S32950 |
|---|---|
| Tensile Strength, min | 690 MPa (100 ksi) |
| Yield Strength, min | 480 MPa (70 ksi) |
| Elongation in 50 mm (2 in.), min | 20% |
| Brinell Hardness, max | 290 HBW |
| Rockwell Hardness, max | 30 HRC |
| Vickers Hardness, max | 290 HV |
| Heat Treatment | 990 °C to 1025 °C (1820 °F to 1880 °F), air cooled |
Set beside UNS S32750 seamless tubes, S32950 is held to a higher elongation minimum, 20% against 15%, while its 690 MPa tensile and 480 MPa yield minimums compare with 800 MPa and 550 MPa for that grade. Below 12.7 mm OD, strip specimens set the elongation values, and Vickers testing is permitted on tube under 9.00 mm inside diameter or under 1.65 mm wall.
Equivalent Designations of UNS S32950 Super Duplex Steel
UNS S32950 super duplex steel is identified by its UNS number and the American product specifications listed here.
- UNSS32950
- ASTM / ASME (tube)ASTM A789 / ASME SA-789
- ASTM / ASME (pipe)ASTM A790 / ASME SA-790
- EN material number (WNR)None assigned
- ASTM common nameNone listed
Order and inspect this grade by its UNS number, S32950: it has no assigned EN material number, and ASTM lists no common name. If a drawing pairs S32950 with a European number, ask the designer to confirm the grade first, as that number identifies a different steel.
S32950 Super Duplex Stainless Steel Seamless Tube Dimensions and Tolerances
Each S32950 super duplex stainless steel seamless tube is produced within our super duplex range of 6 mm to 720 mm OD, 1 mm to 65 mm wall and lengths up to 22 m, quoted in millimeters or inches. ASTM A789 Table 5 sets the permitted variations up to 203.2 mm OD in five size groups:
| Size Group | OD, mm (in.) | OD Variation, mm | Average Wall | Minimum Wall | Cut Length, mm | Thin-Wall Ovality Rule Below |
|---|---|---|---|---|---|---|
| 1 | Under 12.7 (1/2) | ±0.13 | ±15% | +30% / 0 | +3 / 0 | - |
| 2 | 12.7 to under 38.1 (1/2 to 1-1/2) | ±0.13 | ±10% | +20% / 0 | +3 / 0 | 1.6 mm wall |
| 3 | 38.1 to under 88.9 (1-1/2 to 3-1/2) | ±0.25 | ±10% | +20% / 0 | +5 / 0 | 2.4 mm wall |
| 4 | 88.9 to under 139.7 (3-1/2 to 5-1/2) | ±0.38 | ±10% | +20% / 0 | +5 / 0 | 3.8 mm wall |
| 5 | 139.7 to 203.2 incl. (5-1/2 to 8) | ±0.76 | ±10% | +20% / 0 | +5 / 0 | 3.8 mm wall |
Swipe sideways to see the full table.
Tubes thinner than the wall in the last column are treated as thin walled: at any cross section, the largest and smallest diameters may each lie up to double the permitted OD variation away from nominal, as long as the mean diameter of that section still meets the table. Heavy sections get wider wall limits: at 19 mm wall and over, or where the inside diameter is 60% of the OD or less, the limit becomes ±12.5% on average wall or +25.0% / 0 on minimum wall. Tube under 12.7 mm inside diameter that cannot be drawn over a mandrel takes ±15% or +30% / 0.
Industrial Uses of ASTM A789 S32950 Seamless Tubing
Seamless S32950 super duplex steel tube serves typical duplex stainless steel duties in the process industries, chosen where chlorides make stress corrosion cracking the main risk and where the strength of the duplex structure allows a lighter wall.
Oil and Gas Process Exchangers
Process coolers and heat exchangers in oil and gas production and processing are a typical duty for duplex stainless steel, including units on high-pressure process systems.
Heat Exchanger and Condenser Bundles
Straight tube for new shell-and-tube exchanger and condenser bundles is cut to your tube sheet drawing, each super duplex steel S32950 seamless tube held to ASTM A789 OD limits for a consistent fit.
General Corrosive Service Lines
Process and utility tubing in general corrosive service, the duty ASTM A789 is written for, can be specified in S32950 where the design calls for a duplex grade with 26.0 to 29.0% chromium.
Shipping and Packaging for S32950 Seamless Tube Orders
Packing
Export wooden cases or strapped bundles sorted by size, with end caps fitted to every tube.
Marking
Every ASME SA-789 S32950 seamless tube is marked to ASTM A789, including the wall basis (average or minimum), and your item numbers can be added.
Lengths
Up to 22 m straight, or exact cut lengths taken from your bundle drawing.
Paperwork
EN 10204 3.1 (3.2 on request) certificate, packing list and the export documents your customs agent needs.
Trade terms
FOB, CIF or CFR, stated on the quotation.
Delivery area
Thailand, plus export to Singapore, Malaysia, Vietnam, Indonesia, the Philippines and India.
Price of Super Duplex S32950 Seamless Tubing per kg
Super duplex steel UNS S32950 seamless tubes to ASTM A789 are priced against the super duplex seamless tube band, roughly USD 9 to 15 per kg, an indicative figure only. Where your order sits in that band depends on the tube sizes and their wall basis, the cut lengths, how many tubes are listed and any testing added to the A789 minimum, with short lists of small, light-wall tube priced highest. Your tube list brings a firm figure.
Indicative price, Super Duplex Steel UNS S32950 Seamless Tubes
USD 9 to 15 per kg
Indicative only. Send your sizes and specification to Thaida for a firm quotation.
- Outside diameter
- Wall thickness
- Length
- Testing and certification
Ordering Seamless UNS S32950 Tubes from Thaida
Our factory at 154 Moo.1 Map Phai, Ban Bueng, Chonburi 20170, Thailand, produces super duplex steel UNS S32950 seamless tubes, and our sales office at 89/18 Moo.15 Enterprize Park, Bangna-Trad Road, Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand, handles quotations and export paperwork. Each quotation carries a delivery date tied to our production schedule for the sizes you list.
Factory154 Moo.1 Map Phai, Ban Bueng,
Chonburi 20170, Thailand
Chonburi 20170, Thailand
Office89/18 Moo.15 Enterprize Park, Bangna-Trad Road,
Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand
Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand
Exporting to
- Singapore
- Malaysia
- Vietnam
- Indonesia
- Philippines
- India
Seamless S32950 Tubing FAQ
How many S32950 seamless tubes make up one flaring test lot?
One size from one heat. After batch-furnace treatment, the lot is also limited to a single furnace charge. After continuous-furnace treatment, ASTM A789 Table 3 caps it at 125 tubes up to 25.4 mm OD, 75 tubes for larger OD below 50.8 mm or wall under 5.1 mm, and 50 tubes from 50.8 mm OD with 5.1 mm wall upward.
What OD variation should I allow for when drilling tube sheet holes?
Use the A789 band of the tube you specify: ±0.13 mm below 38.1 mm OD, ±0.25 mm from 38.1 to 88.9 mm, ±0.38 mm to 139.7 mm and ±0.76 mm to 203.2 mm for S32950 super duplex stainless steel seamless tube. If a bundle mixes sizes, size each hole set to the band of its own tube.
Is S32950 stronger than the S32205 duplex grade?
Only in tensile strength. ASTM A789 sets 690 MPa tensile for S32950 against 655 MPa for S32205, but the yield minimums are almost level, 480 MPa against 485 MPa, and S32950 needs 20% elongation where S32205 needs 25%. Size the wall from the allowable stress your design code assigns to each grade, not from these minimums alone.
Can I choose eddy current instead of a hydrostatic test for S32950 seamless tubes?
Yes, within the size range the eddy current practice covers. Named on your order, it replaces the hydrostatic test on every tube; an order that names neither leaves the choice to us. The hydrostatic alternative runs at P = 441.2 t/D MPa; the standard asks no more than 7 MPa, and the hold lasts 5 seconds minimum.
How closely are cut lengths held when I retube an existing exchanger?
Never short: A789 allows plus tolerance only. Within 7.3 m the allowance is 3 mm for OD under 38.1 mm and 5 mm for larger OD to 203.2 mm; each started 3 m beyond 7.3 m adds 3 mm, with 13 mm the largest addition. For a retube, state the exact cut length your tube sheets call for.
How does S32950 compare with S32750 for an exchanger design?
S32950 is the richer grade in chromium and the leaner one in nickel and molybdenum: 26.0 to 29.0% Cr against 24.0 to 26.0% for S32750, with 3.5 to 5.2% Ni and 1.00 to 2.50% Mo against 6.0 to 8.0% and 3.0 to 5.0%. Let your corrosion review decide between them; we can quote both on one inquiry.
What does the certificate for a UNS S32950 seamless tube report?
It ties every tube to a heat number, linking the heat analysis checked against ASTM A789 with the tension, flaring and hardness results of that lot. Issued as EN 10204 3.1 (3.2 on request), the certificate also gives the size and the wall basis, average or minimum, that appears in the tube marking.
Can you produce S32950 seamless tube above 203.2 mm OD?
We do, up to 720 mm OD and 65 mm wall, but ASTM A789 Table 5 ends at 203.2 mm, so the OD and wall tolerances for these larger UNS S32950 seamless tube sizes are agreed with you and written into the order before production.
Request a Quote for Super Duplex Steel UNS S32950 Seamless Tubes
or email sales@thaida.co.th