High-Pressure Chemical Reactor Loops
Chemical plants run TP316LN seamless pipe on reactor feed, transfer and high-pressure process lines, where the piping is fabricated by welding and must hold design pressure in corrosive media.
ASTM A312 / ASME SA-312 / UNS S31653 / W.Nr. 1.4429
Stainless Steel 316LN Seamless Pipes Manufacturer in Thailand
Thaida Stainless Steel Manufacturing (Thailand) Co., Ltd. supplies ASTM A312 TP316LN stainless steel seamless pipes made at its Ban Bueng, Chonburi mill, giving pressure and process lines the low carbon of 316L together with nitrogen-raised strength. Under UNS S31653 and WNR 1.4429, it is a nitrogen-alloyed grade within our stainless steel seamless pipes family. Its EN 10204 3.1 (3.2 on request) certificate states the nitrogen content of every heat, and quotations are prepared at our Bang Phli, Samut Prakan office.
Stainless Steel 316LN seamless pipeUNS S31653 / W.Nr. 1.4429
- 6 to 1016 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
Ordering Data for ASTM A312 Stainless Steel 316LN Seamless Pipe
Lines are released either by NPS and schedule or by exact OD and wall, and each ASTM A312 stainless steel 316LN seamless pipe is made to whichever your isometric uses. Below are our size envelope, the delivery condition and the certificate supplied with every order.
- Standard
- ASTM A312 / ASME SA-312
- Grade
- TP316LN (UNS S31653)
- Outside Diameter
- 6 to 1016 mm
- Wall Thickness
- 1 to 65 mm
- Length
- Up to 18 m
- Dimensions
- ASME B36.19M NPS and schedule (Sch 5S, 10S, 40S, 80S), or OD and wall to drawing
- End Type
- Plain or beveled for all schedules, with threads cut only on Sch 40S and 80S
- Surface Finish
- Bright annealed (BA), pickled and passivated, polished, mirror, brushed
- Form
- Seamlesshot or cold finished
- Manufacturing Route
- 1Billet pierced to a hollow shell and hot worked
- 2Then supplied hot finished or cold drawn / cold rolled to size
- Delivery Condition
- Solution annealed at 1040 °C (1900 °F) minimum and rapidly cooled
- Test Certificate
- EN 10204 3.13.2 on request
TP316LN appears in ASTM A312 / ASME SA-312 under UNS S31653, the specification for austenitic stainless steel seamless pipe in general corrosive and high-temperature duty. Each length is made with no welding at any stage, hot or cold finished and delivered free of scale. ASME B36.19M fixes the standard NPS dimensions, though A312 lets a drawing OD and wall be supplied provided all its other requirements are met.
Water pressure or an ET or UT examination proves each ASTM A312 TP316LN stainless steel seamless pipe before it leaves the mill, and every lot also goes through tension and flattening checks. The EN 10204 3.1 (3.2 on request) certificate records the heat chemistry, including the 0.10 to 0.16% nitrogen band, together with the mechanical results. PMI results for every length, the raw material certificate, heat treatment charts and surface roughness and size records go with it; on request we add third-party inspection and a certificate from a government-approved laboratory. Product analysis, impact testing and the ASTM A262 Practice E intergranular corrosion test are added when your order specifies them.
Element Ranges in a UNS S31653 Seamless Pipe Heat
We analyze each heat against the TP316LN row of ASTM A312 and report the result on the certificate of every UNS S31653 seamless pipe. Nitrogen is a required addition of 0.10 to 0.16% rather than an unspecified residual, with carbon capped at 0.035%.
- CrChromium, 16.0 to 18.0
- NiNickel, 10.0 to 14.0
- MoMolybdenum, 2.00 to 3.00
- MnManganese, 2.00 max
- SiSilicon, 1.00 max
UNS S31653316LN
| Element | TP316LN Limit (%) |
|---|---|
| C (Carbon) | 0.035 max |
| Mn (Manganese) | 2.00 max |
| P (Phosphorus) | 0.045 max |
| S (Sulfur) | 0.030 max |
| Si (Silicon) | 1.00 max |
| Cr (Chromium) | 16.0 to 18.0 |
| Ni (Nickel) | 10.0 to 14.0 |
| Mo (Molybdenum) | 2.00 to 3.00 |
| N (Nitrogen) | 0.10 to 0.16 |
How Seamless WNR 1.4429 Pipe Is Tension Tested
Nitrogen held in solid solution adds strength to seamless WNR 1.4429 pipe. Tension tests on each lot are judged against the A312 minimums below, after a 1040 °C (1900 °F) minimum solution anneal and rapid cooling.
| Property | Value |
|---|---|
| Tensile Strength, min | 515 MPa (75 ksi) |
| Yield Strength, min | 205 MPa (30 ksi) |
| Elongation, min, longitudinal | 35% |
| Elongation, min, transverse | 25% |
Stainless Steel 316LN Equivalents by Country
The designations below identify stainless steel 316LN in American, European, Japanese and Chinese standards.
- USA (ASTM / ASME)ASTM A312 / ASME SA-312 TP316LN
- USA (UNS)UNS S31653
- USA (AISI)AISI 316LN
- Europe (EN / WNR)1.4429 / X2CrNiMoN17-13-3
- Japan (JIS)SUS316LN
- China (GB)S31653 (ISC) / 022Cr17Ni12Mo2N
The table is given for cross-reference. Each length of seamless S31653 stainless steel pipe carries the ASTM A312 TP316LN grade marking, and 1.4429 / X2CrNiMoN17-13-3 is the European number to quote when your drawing uses EN designations.
Nitrogen, Carbon and Strength: TP316LN Against TP316L and TP316
Stainless steel 316LN seamless pipe shares its chromium, nickel and molybdenum limits with TP316L and TP316, so the choice between the three comes down to carbon, nitrogen and strength.
| Grade (ASTM A312) | C max (%) | N (%) | Tensile min (MPa) | Yield min (MPa) |
|---|---|---|---|---|
| TP316LN | 0.035 | 0.10 to 0.16 | 515 | 205 |
| TP316L | 0.035 | No requirement | 485 | 170 |
| TP316 | 0.08 | No requirement | 515 | 205 |
Swipe sideways to see the full table.
Against TP316L seamless pipes, 316LN keeps the 0.035% carbon ceiling and raises the minimum yield from 170 MPa to 205 MPa. Against stainless steel 316 seamless pipes, it matches the 515 MPa and 205 MPa minimums but caps carbon at 0.035% instead of 0.08%, which makes the pipe less likely to become sensitized when it is welded. For welded pressure lines that need both properties, TP316LN is the grade to specify.
Schedules and Tolerances for SS 316LN Seamless Pipe
Process and utility lines are usually drawn by NPS and schedule, so we size SS 316LN seamless pipe to ASME B36.19M by default and to a drawing OD and wall when the line calls for it. Exact-OD heat exchanger and instrument work is covered by our 316LN seamless tubes.
Schedule Walls at Five Process Sizes
Wall thickness in mm at five small and medium process sizes. Thread cutting is limited to the two heavier schedules, 40S and 80S; 5S and 10S lengths leave plain or beveled.
| NPS | DN | OD (mm) | Sch 5S | Sch 10S | Sch 40S | Sch 80S |
|---|---|---|---|---|---|---|
| 3/4 | 20 | 26.7 | 1.65 | 2.11 | 2.87 | 3.91 |
| 1-1/4 | 32 | 42.2 | 1.65 | 2.77 | 3.56 | 4.85 |
| 2-1/2 | 65 | 73.0 | 2.11 | 3.05 | 5.16 | 7.01 |
| 4 | 100 | 114.3 | 2.11 | 3.05 | 6.02 | 8.56 |
| 5 | 125 | 141.3 | 2.77 | 3.40 | 6.55 | 9.53 |
Swipe sideways to see the full table.
Wall and OD Limits Under A312
On A312 pipe the allowed wall deviation is set in percent of nominal wall, and the band changes with NPS and with how thick the wall is relative to the OD (t/D):
| NPS | t/D | Wall Tolerance |
|---|---|---|
| 1/8 to 2-1/2 | All | +20.0% / -12.5% |
| 3 to 18 | Up to 5% | +22.5% / -12.5% |
| 3 to 18 | Over 5% | +15.0% / -12.5% |
| 20 and larger | Up to 5% | +22.5% / -12.5% |
| 20 and larger | Over 5% | +15.0% / -12.5% |
OD limits, read by size band:
| NPS (DN) | OD Tolerance (mm) |
|---|---|
| 1/8 to 1-1/2 (DN 6 to 40) | +0.4 / -0.8 |
| Over 1-1/2 to 4 (DN 40 to 100) | +0.8 / -0.8 |
| Over 4 to 8 (DN 100 to 200) | +1.6 / -0.8 |
| Over 8 to 18 (DN 200 to 450) | +2.4 / -0.8 |
| Over 18 to 26 (DN 450 to 650) | +3.2 / -0.8 |
| Over 26 to 34 (DN 650 to 850) | +4.0 / -0.8 |
| Over 34 to 48 (DN 850 to 1200) | +4.8 / -0.8 |
No ordered cut length is delivered short; the over-length allowance is 6 mm (1/4 in), and jointers appear only if your order permits them.
Duties Served by Seamless 1.4429 Stainless Steel Pipe
Seamless 1.4429 stainless steel pipe goes where pressure, corrosive media and site welding meet, from reactor loops to cryogenic transfer lines.
Oil and Petroleum Refining
Refinery and oil processing units install 316LN seamless pipe in process and utility piping exposed to chloride-bearing streams, where its molybdenum resists pitting and crevice corrosion.
Cryogenic Pressure Service
Piping connected to cryogenic pressure vessels for LNG, liquid nitrogen and liquid oxygen is made from seamless 316LN, an austenitic grade that stays tough at low temperature, with no seam to qualify.
Marine and Subsea Equipment
Shipboard seawater lines and subsea equipment take 316LN seamless pipe in moderate chloride service, supplied pickled and passivated and sized by NPS and schedule to suit flanged or butt-welded connections.
Food Processing Equipment
Food processing plants fit seamless 316LN pipe in product and cleaning lines that are welded on site, ordered bright annealed or polished where a smooth internal surface is specified.
Crates, Caps and Stencils for Seamless S31653 Stainless Steel Pipe
Packing
Strapped bundles or wooden cases, plastic end caps on every length, and protective film on polished pipe.
Marking
Our manufacturer's mark, ASTM A312 TP316LN, heat number, NPS or OD with schedule or average wall, SML, plus ET or UT and NH where they apply.
Ends
Plain or beveled to your weld detail, threads cut on Sch 40S and 80S only, all prepared before dispatch together with any cut-to-length work.
Paperwork
One EN 10204 3.1 (3.2 on request) material test certificate per heat, shipped with the packing list.
Terms of sale
FOB, CIF or CFR, fixed in the contract.
Timing
The offer states which items leave from stock and which go into production, with dates.
Budget Figures for Seamless Stainless Steel 316LN Pipe
At an indicative USD 4 to 7.5 per kg, seamless stainless steel 316LN pipe costs a little more than 316L because of nitrogen control and thinner stock of the grade. Nickel and molybdenum set the base, and the line price then shifts with NPS, schedule, length, quantity, finish and added tests such as low-temperature impact testing. For a firm figure, send Thaida your NPS, schedule and tonnage.
Indicative price, Stainless Steel 316LN Seamless Pipes
USD 4 to 7.5 per kg
Indicative only. Send your sizes and specification to Thaida for a firm quotation.
- Schedule
- Length
- Finish
- Quantity
- Testing and certification
- Nickel price
- Molybdenum price
Factory, Office and Export Markets
Seamless 316LN is pierced, finished and tested at our mill at 154 Moo.1 Map Phai, Ban Bueng, Chonburi 20170, Thailand, and line lists for nitrogen-grade or cryogenic work are reviewed by our Samut Prakan office at 89/18 Moo.15 Enterprize Park, Bangna-Trad Road, Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand. From both sites, 316LN stainless steel seamless pipe is shipped to Thai projects and 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
Questions on 316LN Stainless Steel Seamless Pipe
Should a welded line designed on yield strength use TP316LN or TP316L?
TP316LN. A TP316LN heat also meets every TP316L chemistry limit, because TP316L sets no nitrogen requirement, and its 515/205 MPa minimums clear the 485/170 MPa of TP316L. That one-way overlap lets 316LN stand in where 316L is specified, but 316L cannot stand in for 316LN.
How is 316LN told apart from 316L once the lengths are in the yard?
By the nitrogen figure in the heat analysis. ASTM A312 requires 0.10 to 0.16% nitrogen in TP316LN, while TP316L and TP316 carry no nitrogen requirement, so the certificate's nitrogen value, together with the TP316LN grade marking, separates lengths of the three grades stored side by side.
How do I get proof against intergranular attack on welded 316LN seamless lines?
Call up the ASTM A262 Practice E intergranular corrosion test, listed in A312 as supplementary requirement S7, and its result is added to the heat certificate. Because S7 is optional, it is performed only when written into the purchase order, and impact testing can be called up on the same order.
Can seamless 316LN pipe serve LNG and other cryogenic lines?
Yes. For LNG, liquid nitrogen or liquid oxygen piping, name impact testing on the order so the results appear on the manufacturer test certificate, and state the test temperature your design code sets. Low-temperature impact testing adds cost, so include it in the inquiry to get a complete price.
What wall and OD variation applies to NPS 5 Sch 10S seamless pipe?
NPS 5 has a 141.3 mm OD and a Sch 10S wall of 3.40 mm, under 5% of the OD, so the wall may run from 12.5% under to 22.5% over nominal. The OD may be 1.6 mm over or 0.8 mm under. Threads are reserved for Sch 40S and 80S, so order this wall plain or beveled.
Can seamless TP316LN be ordered to a metric OD and wall instead of NPS?
Yes, both routes describe the same product. A drawing that calls 42.2 mm OD by 3.56 mm wall is NPS 1-1/4 Sch 40S, so we quote it under either description. A figure that falls between schedules is made and marked to your OD and wall on the UNS S31653 seamless pipe.
Does the 0.035% carbon cap relax for small-bore or thin-wall TP316LN seamless pipe?
No. ASTM A312 lets TP316L reach 0.040% carbon when the OD is under 12.7 mm or the average wall is under 1.20 mm, because such sizes need many drawing passes, but that allowance is not given to TP316LN. Small-bore and thin-wall TP316LN stays at 0.035% carbon maximum.
Request a Quote for Stainless Steel 316LN Seamless Pipes
or email sales@thaida.co.th