Offshore and Refinery Seawater Coolers
Shell-and-tube coolers and condensers on offshore platforms, in refineries and at power plants pass seawater through the bore, where the chromium, molybdenum and nitrogen of the grade target chloride pitting.
ASTM A789 / ASME SA-789 / UNS S32750 / W.Nr. 1.4410
Super Duplex Steel UNS S32750 Seamless Tubes Manufacturer in Thailand
ASTM A789 UNS S32750 super duplex steel seamless tubes from Thaida Stainless Steel Manufacturing (Thailand) Co., Ltd. are manufactured in Ban Bueng, Chonburi, Thailand, for seawater-cooled heat exchangers, condensers and offshore hydraulic lines. Listed in Europe as W.Nr. 1.4410, the grade must meet the ASTM A789 pitting index minimum of 41 and carries an 800 MPa minimum tensile strength. Quotations and documents for this grade, part of our super duplex steel seamless tubes line, are issued by our Bang Phli, Samut Prakan office.
Super Duplex Steel UNS S32750 seamless tubeUNS S32750 / W.Nr. 1.4410
- 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
Production Range of ASME SA-789 S32750 Seamless Tube
A tube order is defined by four figures: outside diameter, wall (stating average or minimum), length and number of tubes. The table shows the envelope we produce in this grade; NPS and schedule belong to pipe, not tube.
- Standard
- ASTM A789 / ASME SA-789
- Grade
- UNS S32750
- Outside Diameter
- 6 to 720 mm
- Wall Thickness
- 1 to 65 mmaverage or minimum wall
- Length
- Up to 22 mor cut to your length
- Form
- Seamlessround
- End Type
- Plain endbeveled end
- Manufacturing Route
- 1Solid billet hot extruded into seamless tube
- 2Then solution annealed
- Heat Treatment
- 1025 °C to 1125 °C (1880 °F to 2060 °F), rapid cooling in water or by other means
- Test Certificate
- EN 10204 3.13.2 on request
- Testing
- Hydrostatic or nondestructive electric test on every tube
- Tension, flaring and hardness tests per lot
ASTM A789 and its ASME counterpart SA-789 govern this tube, a specification for general corrosion service that gives special emphasis to resistance against stress corrosion cracking. Each ASTM A789 UNS S32750 seamless tube is delivered in the heat-treated condition the standard requires. A789 also flags embrittlement as a risk when ferritic/austenitic steels are held at elevated temperatures for long periods, so include the metal temperature of the duty in your exchanger data. European data sheets name EN 10216-5 for this steel, so a line that calls for seamless WNR 1.4410 tube can be cross-referenced to the A789 order. Headers and spools on the same plant can be built from our UNS S32750 seamless pipes, which follow ASTM A790 and its schedule tables rather than tube tolerances.
Each tube we release is proven individually, by hydrostatic pressure or by a nondestructive electric test, with the method chosen by us when your order is silent on it. Lots of up to 50 tubes get one tension test and larger lots two; per lot, one tube end is expanded with a flaring tool to at least 10% more bore, and hardness is measured on two tubes. In a multi-heat order, every heat is tested separately. Results for each ASTM A789 UNS S32750 seamless tube lot are reported on an EN 10204 3.1 (3.2 on request) certificate, and witnessing by a third-party inspector can be arranged on request.
Seamless S32750 Super Duplex Steel Tube Chemistry and Pitting Index
Values are ASTM A789 limits in % (maximum unless a range is shown). Beyond the element rows, A789 requires Cr + 3.3 × Mo + 16 × N to be at least 41. The heat analysis on the certificate of each seamless S32750 super duplex steel tube lets your inspector recompute that index heat by heat.
- CrChromium, 24.0 to 26.0
- NiNickel, 6.0 to 8.0
- MoMolybdenum, 3.0 to 5.0
- MnManganese, 1.20 max
- SiSilicon, 0.80 max
UNS S32750S32750
| Element | UNS S32750, ASTM A789 (%) |
|---|---|
| C (Carbon) | 0.030 max |
| Mn (Manganese) | 1.20 max |
| P (Phosphorus) | 0.035 max |
| S (Sulfur) | 0.020 max |
| Si (Silicon) | 0.80 max |
| Ni (Nickel) | 6.0 to 8.0 |
| Cr (Chromium) | 24.0 to 26.0 |
| Mo (Molybdenum) | 3.0 to 5.0 |
| N (Nitrogen) | 0.24 to 0.32 |
| Cu (Copper) | 0.50 max |
Super Duplex Steel S32750 Seamless Tube Strength and Hardness
For S32750, ASTM A789 Table 4 gives one row of limits for every tube size, checked on each lot after solution annealing.
| Requirement | UNS S32750, ASTM A789 |
|---|---|
| Tensile Strength, min | 800 MPa (116 ksi) |
| Yield Strength, min | 550 MPa (80 ksi) |
| Elongation in 2 in. or 50 mm, min | 15% |
| Brinell Hardness, max | 300 HBW |
| Rockwell Hardness, max | 32 HRC |
| Vickers Hardness, max | 300 HV |
Cross-Reference Designations for UNS S32750 Super Duplex Steel
Each row pairs UNS S32750 super duplex steel with the name it carries in an ASTM, EN or GB document, so a foreign data sheet can be matched to it.
- UNSS32750
- ASTM / ASME (tube)ASTM A789 / ASME SA-789
- ASTM common name2507
- EN number (WNR)1.4410
- EN steel nameX2CrNiMoN25-7-4 (EN 10216-5)
- China (GB)022Cr25Ni7Mo4N; ISC S25073
An order for seamless 1.4410 super duplex tube should still name UNS S32750 and ASTM A789, because the pitting index rule, the 300 HV hardness ceiling and the tolerance table below are ASTM A789 requirements. A line list written around seamless WNR 1.4410 tube receives an offer in UNS S32750 to A789, with the EN and GB names used only to match documents.
Selecting Seamless S32750 Against Other A789 Duplex Grades
Within ASTM A789, the closest alternative is the tungsten and copper alloyed grade supplied as UNS S32760 seamless tubes. Its pitting index is held to the same floor of 41 but adds half the tungsten content (0.50 to 1.00%) to molybdenum, its solution annealing window is higher at 1070 to 1140 °C against 1025 to 1125 °C for S32750, and its hardness ceiling is 310 HBW against 300 HBW. A step down in alloy, duplex UNS S32205 seamless tubes offer a 485 MPa minimum yield and carry no pitting index requirement in A789.
OD, Wall and Length Tolerances for S32750 Super Duplex Stainless Steel Seamless Tube
Our S32750 super duplex stainless steel seamless tube is made in OD sizes between 6 and 720 mm, yet ASTM A789 lists permitted variations only to 203.2 mm OD. Beyond 203.2 mm, OD and wall tolerances are agreed with you at the quotation stage.
| OD Band, mm (in.) | OD Tolerance, mm | Average Wall | Minimum Wall | Cut Length, mm | Thin-Wall Limit |
|---|---|---|---|---|---|
| Under 12.7 (under 1/2) | ±0.13 | ±15% | +30% / 0 | +3 / 0 | Not set |
| 12.7 to under 38.1 (1/2 to under 1-1/2) | ±0.13 | ±10% | +20% / 0 | +3 / 0 | Under 1.6 mm wall |
| 38.1 to under 88.9 (1-1/2 to under 3-1/2) | ±0.25 | ±10% | +20% / 0 | +5 / 0 | Under 2.4 mm wall |
| 88.9 to under 139.7 (3-1/2 to under 5-1/2) | ±0.38 | ±10% | +20% / 0 | +5 / 0 | Under 3.8 mm wall |
| 139.7 to 203.2 incl. (5-1/2 to 8) | ±0.76 | ±10% | +20% / 0 | +5 / 0 | Under 3.8 mm wall |
Swipe sideways to see the full table.
A tube thinner than the limit in the last column may show individual diameter readings up to twice the listed OD tolerance, provided the mean diameter stays inside the table. Heavy-wall tube follows different wall limits: once the wall reaches 19 mm, or the bore is no larger than 60% of the OD, an average-wall order is held to ±12.5% and a minimum-wall order to +25% / 0.
Heat Exchanger and Offshore Uses of Seamless WNR 1.4410 Tube
The grade is specified for heat transfer and control-line service in which chlorides and pressure act on the same tube.
Hydraulic Control Lines and Umbilicals
Small-OD tube from 6 mm carries hydraulic control fluid in subsea umbilicals and topside control lines, where the 550 MPa minimum yield lets a thin wall hold high working pressure.
Desalination Flash and Reverse Osmosis Units
Multi-stage flash units and high-pressure reverse osmosis systems in seawater desalination plants use this grade in concentrated, chloride-rich brine, a duty that calls for resistance to chloride pitting and stress corrosion cracking.
Acid Plant Exchangers and Reactors
Chemical plants fit super duplex steel S32750 seamless tube in exchangers and reactors handling sulfuric or phosphoric acid and mixed acid and chloride streams, ordered to each exchanger's OD and wall basis.
Sour Gas Exchanger Bundles
Oil and gas operators tube coolers and exchangers on sour gas trains with the grade, where pressure, chlorides and hydrogen sulfide act together on every tube in the bundle.
Flue Gas Cleaning and Bleach Plants
Pulp mill digesters and bleach plants, along with flue gas cleaning units at power and industrial sites, use the tube for heat exchange in acidic, chloride-bearing liquors and condensates.
Bundling and Export of Seamless 1.4410 Super Duplex Tube
Bundling
Tubes sorted by size into strapped bundles or wooden cases, with end caps keeping each bore clean.
Marking
Each tube carries its heat number, OD, wall with the basis it was ordered to, the grade and ASTM A789.
Long tubes
Lengths of up to 22 m travel in cases or bundles with spaced timber supports so they arrive straight.
Documents
One EN 10204 3.1 (3.2 on request) certificate per heat and lot, a size-by-size packing list and the commercial invoice.
Independent checks
On request, an inspector you appoint can examine the tubes at our mill before loading.
Sale terms
FOB, CFR or CIF, chosen by you at inquiry.
Destinations
Thai plant sites by road, and sea freight to Singapore, Malaysia, Vietnam, Indonesia, the Philippines and India.
Indicative Price of Seamless S32750 Super Duplex Tubing
Super Duplex Steel UNS S32750 Seamless Tubes currently trade at roughly USD 9 to 15 per kg on the open market, an indicative band rather than a quotation. Small OD, thin wall, tight tolerance requests and short runs push the figure toward the top of that band, while larger, heavier sizes ordered in quantity sit lower. Thaida confirms a firm price for each size once your tube list arrives.
Indicative price, Super Duplex Steel UNS S32750 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
- Quantity
Mill, Office and Quotations for UNS S32750 Seamless Tubes
Extrusion, heat treatment and testing take place at our factory, 154 Moo.1 Map Phai, Ban Bueng, Chonburi 20170, Thailand. Our office at 89/18 Moo.15 Enterprize Park, Bangna-Trad Road, Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand, writes each price offer and issues the test certificates and dispatch papers that travel with the tubes. Lead times for Super Duplex Steel UNS S32750 Seamless Tubes follow our extrusion schedule, and sizes already on hand are flagged in the offer.
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 S32750 Tube Questions from Exchanger and Offshore Projects
Which A789 tolerance band covers a 50.8 mm OD S32750 seamless tube?
The 38.1 to under 88.9 mm band, which holds the OD to ±0.25 mm and allows ±10% on average wall or +20% / 0 on minimum wall. With a wall under 2.4 mm, single diameter readings may reach twice that OD figure, provided the mean stays within ±0.25 mm.
Who decides between the hydrostatic and electric test on each seamless S32750 tube?
You do, if the order names the method; otherwise ASTM A789 leaves the choice to us. If hydrostatic, each tube holds P = 441.2 × t/D MPa for 5 seconds or more, where t is the wall and D the OD in millimeters, with 7 MPa as the ceiling. The electric alternative uses ASTM E213, E309, E426 or E570 practice.
For a retube in S32750 seamless tubing, should the wall be average or minimum?
Use the basis your original exchanger design used. Average wall is held to ±10% (±15% under 12.7 mm OD), while minimum wall allows +20% / 0 (+30% / 0) and never runs under the stated figure. A minimum-wall tube is therefore heavier for the same nominal wall, and the tube marking records which basis applies.
What cut-length allowance applies once seamless S32750 tubing passes 7.3 m?
The table plus limit grows by 3 mm for every 3 m, or fraction of 3 m, past 7.3 m, up to a maximum extra 13 mm; nothing is allowed on the minus side. Straight lengths can be ordered up to 22 m, so state the exact length your exchanger drawing requires.
Can a bundle first tubed in S32760 take seamless S32750 replacements?
Dimensionally yes: both grades are made to ASTM A789 with the same OD and wall tolerances, so replacement tubes fit the existing tube sheet. The material change itself needs approval from whoever owns the exchanger design, because its calculations and corrosion review were written for S32760. Send both data sheets and we quote either grade.
Do A789 tensile and hardness rules still apply to 6 mm OD seamless S32750 hydraulic tube?
Yes. A789 lifts its mechanical requirements only below 3.2 mm OD or 0.4 mm wall. For small sizes it permits Vickers testing below 9.00 mm ID or 1.65 mm wall, with a 300 HV limit for S32750, and applies strip-specimen elongation values under 12.7 mm OD.
Does ASTM A789 require a corrosion test on S32750 seamless tube?
No. A789 sets no corrosion test for seamless tube and controls pitting resistance through the composition rule attached to the chemistry table instead. If your project specification adds a corrosion test, list the method and acceptance criteria on the inquiry so that it is agreed and priced before production starts.
Request a Quote for Super Duplex Steel UNS S32750 Seamless Tubes
or email sales@thaida.co.th