S31603 Stainless Steel Pipe
1. Standard: ASTM A312、ASME SA312
2. Diameters: From 1/8 inch to 30 inch.
3. Wall thickness: SCH 10S, SCH40S, SCH80S
4. Length: Single Random Length, Double Random Length and Customized
S31603 Stainless Steel Pipe is the workhorse low-carbon austenitic stainless grade for welded piping systems exposed to chloride-bearing environments, pharmaceutical process fluids, and moderate sour service.
The "L" is the critical character - capping carbon at 0.030% maximum prevents chromium-carbide precipitation at the weld heat-affected zone, which means welded 316L pipe keeps its intergranular corrosion resistance without requiring post-weld solution annealing. That single metallurgy change is why 316L dominates welded stainless piping in oil and gas, chemical processing, food-grade and pharmaceutical plants, and marine engineering.
Product Forms
Bar & Rod
Plate & Sheet
Coil & Strip
Pipe & Tube
Fitting: Flange, Tee, Elbow, Reducer etc.
Forging: Ring, Shaft, Circle, Block etc.
Standards & Equivalents - One Pipe, Four Standard Series
316L stainless pipe doesn't sit under a single ASTM designation. It crosses four product-form standards and several equivalent systems globally. Know which one you're buying before you issue the PO.
| Standard Family | Product Form | Common Use |
|---|---|---|
| ASTM A312 / ASME SA312 | Seamless and welded austenitic pipe for high-temperature and general corrosive service | The default for industrial stainless process piping |
| ASTM A358 | Electric-fusion-welded (EFW) austenitic pipe for high-temperature and corrosive service | Larger diameters, typically NPS 8" and above |
| ASTM A213 / ASME SA213 | Seamless ferritic and austenitic boiler, superheater, and heat-exchanger tubes | Heat exchangers, boiler tubes, smaller OD precision tubing |
| ASTM A269 | Seamless and welded austenitic tubing for general service | Low and high-temperature instrumentation, sanitary lines |
| EN 10216-5 | Seamless steel tubes for pressure purposes - stainless | European buyer equivalent of A312 seamless |
| EN 10217-5 | Welded steel tubes for pressure purposes - stainless | European buyer equivalent of A312 welded |
| EN 10296-2 | Welded stainless steel tubes for mechanical and structural | European structural / mechanical applications |
Chemical Composition (UNS S31603 / 1.4404 / 316L)
| Element | Content (%) - ASTM A312 TP316L |
|---|---|
| Carbon (C) | ≤ 0.030 |
| Chromium (Cr) | 16.0 – 18.0 |
| Nickel (Ni) | 10.0 – 14.0 |
| Molybdenum (Mo) | 2.0 – 3.0 |
| Manganese (Mn) | ≤ 2.00 |
| Silicon (Si) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Nitrogen (N) | ≤ 0.10 |
| Iron (Fe) | Balance |
Mechanical Properties (Room Temperature, Solution-Annealed Condition)
| Property | ASTM A312 TP316L Minimum | Typical |
|---|---|---|
| Tensile strength | 485 MPa (70 ksi) | 550–620 MPa |
| Yield strength (0.2% offset) | 170 MPa (25 ksi) | 200–280 MPa |
| Elongation in 50mm | 35% | 45–55% |
| Hardness (Brinell) | ≤ 217 HB | 160–190 HB |
| Density | - | 7.98 g/cm³ |
At cryogenic temperatures, 316L retains useful ductility and toughness down to -196°C, making it suitable for LNG boil-off gas lines, ammonia lines, and low-temperature process piping. The 170 MPa yield floor set by ASTM A312 is conservatively low - actual production 316L typically tests at 200-280 MPa.
Available Product Range at HUITONG
| Parameter | Range |
|---|---|
| Manufacturing type | Seamless (cold-drawn and hot-rolled), ERW welded, EFW welded, cold-drawn precision tubing |
| Outer diameter (OD) | 1/8" – 48" (DN6 – DN1200) |
| Wall thickness (schedule) | Sch 5S, 10S, 40S, 80S, 160, XXS |
| Length | Single random (5-7m), double random (11-13m), cut-to-length up to 18m |
| Surface finish | Pickled & passivated, bright annealed (BA), mill finish, polished (180G-600G) |
| End finish | Plain end (PE), beveled end (BE) per ASME B16.25, threaded (NPT/BSPT) |
| Heat treatment condition | Solution annealed (mandatory) per ASTM A312 |
Corrosion Performance: What 316L Really Gives You
Pitting Resistance (ASTM G48 Method A)
ASTM G48 critical pitting temperature (CPT) testing is the practical way to compare stainless grades in chloride service:
| Grade | PREN | CPT (°C) in 6% FeCl₃ | Seawater Pitting Index |
|---|---|---|---|
| 304 / 1.4301 | 18 | 15-20 | Limited |
| 316 / 1.4401 | 24 | 25-30 | Moderate |
| 316L / 1.4404 | 24 | 25-30 | Moderate |
| 904L / 1.4539 | 35 | 45-50 | Good |
| 254 SMO / 1.4547 | 43 | 60-70 | Excellent |
| Duplex 2205 / 1.4462 | 35 | 45-55 | Good |
| Super duplex 2507 / 1.4410 | 42 | 70-80 | Excellent |
316L is acceptable in static and slow-moving seawater up to about 25°C. Above 25°C, in chlorinated cooling water, or in systems with biofouling, 316L begins to pit and the upgrade path is duplex 2205 → super duplex 2507 → 254 SMO.
Crevice Corrosion
Seawater and chloride-bearing process fluids cause crevice corrosion at flange faces, gasket grooves, and under deposits before they cause general pitting. 316L handles crevice corrosion roughly 50% better than 304 but is still vulnerable below about 15°C in stagnant service.
Sour Service (NACE MR0175 / ISO 15156 Part 3)
316L in the solution-annealed condition is approved for sour service under NACE MR0175 / ISO 15156 Part 3, with these limits:
- Hardness ≤ 22 HRC
- Cold work below 5% (no severe forming)
- Use in chloride-free or low-chloride H2S environments per the standard
For above-22-HRC or heavily cold-worked applications - including some cold-drawn precision tubing - the material falls outside NACE MR0175 in its as-produced condition and may require stress-relief or other qualification.
- For higher-pressure / higher-temperature sour service, step up to:
- Duplex 2205 or super duplex 2507 for chloride + H2S combination
- Inconel 625, Inconel 825 for higher H2S partial pressure and temperature
- Hastelloy C276 for severe sour + chloride service
Application Map - Where 316L Is the Right Spec
| Industry | Service | Why 316L |
|---|---|---|
| Oil and gas | Instrument air, sampling, low-pressure process piping | NACE MR0175 compliance in annealed condition, weldability |
| Chemical processing | Heat exchanger tubes, condenser tubing, mild acid handling | Mo provides chloride margin |
| Pharmaceutical / biotech | WFI (water for injection), purified water loops, clean steam | Low carbon for welded systems with CIP/SIP |
| Food and beverage | Brewery process lines, dairy piping, CIP loops | Hygienic surface finishes, weldability |
| Marine engineering | Deck piping, above-waterline fittings, ballast handling | 316L over 304 for chloride margin |
| Desalination | Pretreatment and low-pressure sections | Acceptable in 25°C and below |
| Architectural / construction | Coastal handrails, balustrades, structural | Aesthetic and corrosion combined |
| Hydraulics and pneumatics | Precision tubing | Cold-drawn 316L / 316L to ASTM A213 |
Quality Assurance and Documentation
All HUITONG 316L pipe shipments are produced under:
- ISO 9001:2015 quality management with documented traceability from melt to shipment
- PED 2014/68/EU compliance for European destinations - Notified Body CE marking on request
- NACE MR0175 / ISO 15156 declarations for annealed-condition sour service
- EN 10204 3.1 MTC as standard; 3.2 with TÜV or BV verification on request
- ASTM A262 Practice A/E intergranular corrosion testing on request (for H₂SO₄ + Fe₂(SO₄)₃ corrosion sensitivity verification)
- ASTM A262 Practice C (Huey test - 65% boiling nitric acid) for nitric-acid service
- Dimensional and visual inspection per ASME B36.19 / B36.10
- Hydrostatic testing at mill per ASTM A312 (or A358 for welded)
- Eddy current testing per ASTM A312 on all cold-drawn precision tubing
- PMI verification on each bundle and on heat-transfer boundaries
- SGS / Bureau Veritas / TÜV / DNV third-party inspection available on owner request
FAQ
Q: About S31603 Stainless Steel Pipe price per kg?
A: Prices ranges from $3 to $8 per kg, vary depending on size, wall thickness, supplier etc.
Q: How long does your delivery time take?
A: Delivery time is within 5-21 days
Q: Is There Sample Service?
A: Samples Are Provided Free Of Charge
Q: What Is The Minimum Order Quantity?
A: No Minimum Order Quantity
Q: How to pack the products?
A: The inner layer has a waterproof paper outer layer and is fixed with a fumigation wooden pallet.
Q: Exported Countries
A: Brazil, South Africa, Indonesia, India, Singapore, Malaysia, Iran, Russia, UAE, Chile, Laos, etc
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