Oil and Gas Production Lines
Flowlines, topside process pipelines and produced-water piping on offshore platforms and onshore plants are run in S31803, where chlorides, pressure and spool weight together narrow the choice of pipe material.
ASTM A790 / ASME SA-790 / UNS S31803 / W.Nr. 1.4462
Duplex Steel UNS S31803 Seamless Pipes Manufacturer in Thailand
We are Thaida Stainless Steel Manufacturing (Thailand) Co., Ltd., a manufacturer of ASTM A790 UNS S31803 duplex steel seamless pipes based in Ban Bueng, Chonburi, Thailand, with our sales office in Bang Phli, Samut Prakan. UNS S31803, listed as W.Nr. 1.4462 in European standards, is the original 22Cr duplex grade, and many existing plant and maintenance specifications still name it for replacement spools, process lines and produced-water piping. The grade belongs to our seamless duplex steel pipe range.
Duplex Steel UNS S31803 seamless pipeUNS S31803 / W.Nr. 1.4462
- 6 to 720 mmOutside diameter
- 1 to 65 mmWall thickness
- Up to 18 mLength
- EN 10204 3.1Test certificate
EN 10204 3.1 certificate / 3.2 on request
ASTM A790 UNS S31803 Seamless Pipe Specifications
All values below apply to UNS S31803 made to ASTM A790 / ASME SA-790. Small-bore branches and full-size headers both come from this range, specified either as NPS and schedule or as OD and wall to your drawing.
- Standard
- ASTM A790 / ASME SA-790
- Grade
- UNS S31803
- Outside Diameter
- 6 to 720 mm
- Wall Thickness
- 1 to 65 mm
- Length
- Up to 18 mor cut to length
- Dimensions
- NPS and schedule per ASME B36.19M, or OD and wall to drawing
- End Type
- Plain endbeveled end; threaded end on Sch 40S and heavier
- Form
- Seamless
- Manufacturing Route
- 1Solid round bar heated and pierced into a hollow shell
- 2Then hot finished or cold finished
- Heat Treatment
- Solution annealed at 1020 to 1100 °C, rapidly cooled in water or by other rapid means
- Surface
- Pickled free of scaleor bright annealed
- Testing
- Hydro test or ultrasonic / eddy current inspection on each pipe
- Lot tests for tension, flattening and hardness
- Test Certificate
- EN 10204 3.13.2 on request
ASTM A790 / ASME SA-790 covers pipe for general corrosive service, with stress corrosion cracking resistance as its stated focus; unless the order states otherwise, every length must be supplied heat treated. Appendix X1 of the standard tabulates Schedules 5S, 10S, 40S and 80S by NPS, and pipe outside those dimensions can still be supplied provided it complies with the rest of A790. Exchanger bundles ordered by OD and tube tolerances are covered by our UNS S31803 seamless tubes to ASTM A789 instead.
A790 sets the release tests by lot. A lot of up to 100 pipes gets one tension test and a larger lot two; 5% of the pipe in each lot is flattened, and two pipes per lot are hardness tested by Brinell or Rockwell. On top of the lot tests, every ASME SA-790 S31803 seamless pipe is proved individually, by hydrostatic test or by ultrasonic or eddy current inspection. Our EN 10204 3.1 (3.2 on request) material test certificate records these results with the heat analysis; PMI on each length and heat treatment charts are supplied with it, and an independent inspector can witness tests on request.
Chemical Composition of Seamless S31803 Duplex Steel Pipe
ASTM A790 sets the limits below for UNS S31803, as maximums unless a range is shown; copper is not specified for this grade. The steel maker's heat analysis is reported on the certificate, and your inspector can ask for a product analysis on two pipes from each lot.
- CrChromium, 21.0 to 23.0
- NiNickel, 4.5 to 6.5
- MoMolybdenum, 2.5 to 3.5
- MnManganese, 2.00 max
- SiSilicon, 1.00 max
UNS S31803S31803
| Element | UNS S31803 Limit per ASTM A790 (%) |
|---|---|
| C (Carbon) | 0.030 max |
| Mn (Manganese) | 2.00 max |
| P (Phosphorus) | 0.030 max |
| S (Sulfur) | 0.020 max |
| Si (Silicon) | 1.00 max |
| Ni (Nickel) | 4.5 to 6.5 |
| Cr (Chromium) | 21.0 to 23.0 |
| Mo (Molybdenum) | 2.5 to 3.5 |
| N (Nitrogen) | 0.08 to 0.20 |
Mechanical Properties of S31803 Duplex Stainless Steel Seamless Pipe
Wall calculations for S31803 duplex stainless steel seamless pipe start from these A790 minimums. Compared with 316L seamless pipes, the 450 MPa yield floor is about double, which often allows a thinner schedule at an equal design pressure.
| Property | Value | Unit |
|---|---|---|
| Tensile Strength, min | 620 (90) | MPa (ksi) |
| Yield Strength, min | 450 (65) | MPa (ksi) |
| Elongation in 2 in. or 50 mm, min | 25 | % |
| Hardness, max (Brinell) | 290 | HBW |
| Hardness, max (Rockwell C) | 30 | HRC |
Equivalent Designations of Duplex S31803
Drawings and data sheets from other standard systems identify duplex S31803 by these names.
- UNSS31803
- ASTM / ASME pipe specificationASTM A790 / ASME SA-790
- EN steel number1.4462
- EN steel nameX2CrNiMoN22-5-3
- EN seamless pipe standardEN 10216-5
- JISSUS329J3L (JIS G3459)
- GB022Cr22Ni5Mo3N; older designation 0Cr22Ni5Mo3N (GB/T 14976)
- Common nameDuplex 2205
Small and Mid-Bore Sizes of Seamless S31803 Duplex Pipe
Our Duplex Steel UNS S31803 Seamless Pipes span 6 mm to 720 mm in OD and 1 mm to 65 mm in wall, with single lengths reaching 18 m. The schedule table covers the small and mid bores used for process branches, drains and replacement spools; larger NPS and drawing sizes are made within the same range.
Schedule Walls, NPS 1/2 to 3
Schedule walls in mm, as tabulated in ASTM A790 Appendix X1:
| NPS | DN | OD (mm) | Sch 10S | Sch 40S | Sch 80S |
|---|---|---|---|---|---|
| 1/2 | 15 | 21.34 | 2.11 | 2.77 | 3.73 |
| 3/4 | 20 | 26.67 | 2.11 | 2.87 | 3.91 |
| 1 | 25 | 33.40 | 2.77 | 3.38 | 4.55 |
| 1-1/2 | 40 | 48.26 | 2.77 | 3.68 | 5.08 |
| 2 | 50 | 60.33 | 2.77 | 3.91 | 5.54 |
| 3 | 80 | 88.90 | 3.05 | 5.49 | 7.62 |
Swipe sideways to see the full table.
OD and Wall Tolerances up to NPS 8
Permitted variations on A790 pipe are set by NPS and, from NPS 3 upward, by the wall-to-OD ratio (t/D):
| NPS (DN) | OD Tolerance (mm) | Wall Tolerance (% of nominal) |
|---|---|---|
| 1/8 to 1-1/2 (DN 6 to 40) | +0.4 / -0.8 | +20.0 / -12.5 |
| Over 1-1/2 to 2-1/2 (over DN 40 to 65) | +0.8 / -0.8 | +20.0 / -12.5 |
| 3 to 4 (DN 80 to 100), t/D up to 5% | +0.8 / -0.8 | +22.5 / -12.5 |
| 3 to 4 (DN 80 to 100), t/D over 5% | +0.8 / -0.8 | +15.0 / -12.5 |
| Over 4 to 8 (over DN 100 to 200), t/D up to 5% | +1.6 / -0.8 | +22.5 / -12.5 |
| Over 4 to 8 (over DN 100 to 200), t/D over 5% | +1.6 / -0.8 | +15.0 / -12.5 |
Above NPS 8 the minus OD tolerance stays at 0.8 mm while the plus side widens to 2.4 mm, 3.2 mm and 4.0 mm across the DN bands up to DN 850, and wall tolerance keeps the same t/D split. Ordered cut lengths may run up to 6 mm (1/4 in.) long but never short.
Fabricating and Welding Seamless 1.4462 Duplex Pipe
Seamless 1.4462 duplex pipe leaves the mill solution annealed, rapidly cooled and either pickled free of scale or bright annealed, so spool fabrication starts directly with cutting, beveling and fit-up. For a replacement spool, matching the NPS, schedule and end preparation of the original line lets the new section be tied in with one field weld at each end.
Field and shop welds on duplex steel S31803 seamless pipe normally stay in the as-welded condition. If your code requires a solution anneal after welding for a critical service, write it into the order. A790 also cautions that these steels can embrittle after prolonged exposure to elevated temperatures, so confirm the design temperature at the grade selection stage.
Service Duties for Duplex Steel S31803 Seamless Pipe
S31803 is specified for pressurized process and utility lines that carry chlorides, from offshore production to pulp mills.
Chemical Plant Acid and Chloride Service
Acid and chloride service lines in chemical plants run in seamless S31803 duplex steel pipe, welded into skids, headers and pipe racks around the pressure vessels they serve.
Seawater and Cooling Water Piping
Seawater piping and cooling water lines on platforms, ships and coastal plants, including the supply and return runs of seawater-cooled heat exchangers, are laid in S31803 to resist chloride attack.
Desalination Plant Branch Lines
Brine and seawater branch lines, drains and small-bore connections around the high-pressure pumps of desalination plants are made up in S31803, welded or threaded to suit the schedule.
Pulp and Paper Mills
Pulp and paper mills run bleaching plant piping, pulp digestion circuits and chemical recovery lines in S31803, with seamless lengths cut and beveled for spool work during mill shutdowns.
Replacement Spools in Existing Plants
Plants built to older specifications that name UNS S31803 replace worn or modified sections in the same grade, so the line class, documentation and qualified weld procedures stay unchanged.
Crating, Marking and Shipment of Seamless WNR 1.4462 Pipe
Small-bore lengths
Grouped by size and heat into tied bundles, with wooden or plywood cases for bright annealed or heavy-wall pipe.
Identification
Stencil marking of grade, heat number and size on each length, plus barcode labels or your own tagging scheme where required.
Ends
Every bevel, thread and plain end closed with a plastic cap before loading.
Incoterms
FOB, CIF or CFR, priced to the discharge port named in your inquiry.
Certificates
EN 10204 3.1 (3.2 on request) papers covering every heat in the shipment go with the shipping documents.
ASME SA-790 S31803 Seamless Pipe Price per kg
For budgeting, this grade is quoted in the market at USD 5 to 11 per kg; treat that as an indicative range, not an offer. Small-bore sizes and heavy Sch 80S walls sit at the upper end, while the schedule mix, lengths, quantity and any extra inspection settle the final figure. Every line item on your size list receives its own firm quote.
Indicative price, Duplex Steel UNS S31803 Seamless Pipes
USD 5 to 11 per kg
Indicative only. Send your sizes and specification to Thaida for a firm quotation.
- Outside diameter
- Wall thickness
- Schedule
- Length
- Quantity
- Testing and certification
Production in Chonburi and Export from Thailand
The mill at 154 Moo.1 Map Phai, Ban Bueng, Chonburi 20170, Thailand, is where our Duplex Steel UNS S31803 Seamless Pipes are made. Order tracking, quotations and certificate issue run through our office at 89/18 Moo.15 Enterprize Park, Bangna-Trad Road, Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand. Plants throughout Thailand are supplied straight from Ban Bueng, and the same grade is exported to Singapore, Malaysia, Vietnam, Indonesia, the Philippines and India.
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
FAQ on Specifying S31803 Seamless Pipe
Can S31803 seamless pipe go into a line class written for S32205?
Only if its certificate also shows S32205 compliance. An S31803 heat may contain as little as 21.0% chromium, 2.5% molybdenum and 0.08% nitrogen, all below the S32205 minimums, and its tensile minimum is 620 MPa against 655 MPa. Dual-certified pipe meeting both grades is available on request when one stock has to serve both line classes.
What should a welding procedure for UNS S31803 seamless pipe control?
Filler metal, heat input and interpass temperature. Use a matching duplex filler and keep heat input and interpass within the range your duplex procedure qualification established, since together they set the ferrite-austenite balance in the weld and heat-affected zone. Ferrite content measurement can be added to the order where your project requires it.
Which hardness limit applies to S31803 seamless pipe in sour service?
ASTM A790 caps the grade at 290 HBW or 30 HRC. Sour-service standards add their own hardness and environmental limits on top of that cap, so name the governing document on the order, and the hardness results for each lot are checked against both requirements before release.
How long can single lengths of S31803 seamless pipe be supplied?
Up to 18 m. Long single lengths cut the number of field welds on pipe racks, seawater runs and flowlines, and A790 allows no jointers unless the order permits them, so every length arrives as one continuous seamless piece. For prefabricated spools, give exact cut lengths instead.
How is the hydrostatic test pressure set for S31803 seamless pipe?
With P = 2St/D, where t is the wall, D the OD and S is 225 MPa, half the 450 MPa minimum yield. Every size in our schedule table is 88.9 mm OD or less, so the pressure need not exceed 17.0 MPa; larger pipe caps at 19.0 MPa. Unless your order names hydro, an electric test may replace it.
Can small-bore S31803 seamless pipe be ordered on minimum wall?
Yes. For NPS 1/8 to 2-1/2, a minimum-wall order allows up to 32.5% over and nothing under the specified wall, instead of +20.0 / -12.5% on nominal wall. It suits pressure designs that cannot absorb any under-tolerance; state minimum wall and the figure in mm on each line item.
Request a Quote for Duplex Steel UNS S31803 Seamless Pipes
or email sales@thaida.co.th