Seamless Stainless Steel TP317 Pipe
ASTM A312 TP317 Pipe | UNS S31700 / EN 1.4449 Manufacturer
Product Overview
TP317 Seamless Stainless Steel Pipe is supplied for higher molybdenum content than 316 for aggressive chemical service. The size range shown (OD 6–1016 mm; WT 0.5–65 mm) is the overall capability across this product family, not a per-grade commitment. Confirm the specific OD × WT × length combination for the ordered grade in the quotation. The governing specification must be stated on the purchase order: ASTM A312 / ASME SA312. Chemistry, mechanical properties, heat treatment, dimensional tolerance, NDT and certification must be reported against the ordered standard and material heat; do not treat typical values as guaranteed acceptance limits.
Manufactured from a solid billet through a seamless process, TP317 pipes feature:
- No longitudinal weld seams
- Uniform wall thickness
- Enhanced structural integrity
- Higher pressure-bearing capacity
Compared to welded pipe of the same grade and wall thickness, TP317 seamless pipe has no longitudinal weld seam; whether this translates into a longer service life depends on the actual service conditions, corrosion allowance and design basis.
Why Choose TP317 Seamless Pipe?
High Molybdenum Content (≥ 3.0%)
Improves resistance to:
- Pitting corrosion
- Crevice corrosion
- Chloride-induced attack
Upgraded Alternative to 316 / 316L
TP317 offers superior performance compared to standard 316 grades:
- Better resistance to sulfuric and phosphoric acids
- Improved durability in aggressive chemical environments
High Structural Reliability
The seamless construction has no longitudinal weld seam, so there is no weld-joint efficiency factor to apply:
- Allowable design pressure is calculated from the governing design code, the selected grade and the actual wall thickness
- No longitudinal weld joint to be assessed in pressure design
Excellent Fabrication & Weldability
- Good ductility for bending and forming
- Compatible with standard industrial welding methods
Key Advantages of TP317 Stainless Steel Pipe
1. Superior Corrosion Resistance
Performs exceptionally well in:
- Chloride-rich environments
- Sulfuric acid systems
- Phosphoric acid processing
2. High Pressure & Mechanical Strength
- No longitudinal weld seam
- Suitable for critical pipelines and pressure systems
3. Service Life and Reliability
- Reduced maintenance costs
- Improved lifecycle performance in harsh conditions
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for TP317 stainless steel.
Equivalent Grade
| UNS | Common grade name | EN material number | EN steel name | JIS grade | GB/T grade |
|---|---|---|---|---|---|
| S31700 | 317 | – (direct EN match not confirmed) | – | SUS317 | 06Cr19Ni13Mo3 |
Grade correspondence does not make ASTM, ASME, EN, JIS and GB delivery requirements interchangeable. Confirm chemistry, heat treatment, mechanical properties, dimensions, testing and certification against the purchase specification. See the grade designation index.
Chemical Composition
The composition of Stainless Steel 317 is carefully balanced to achieve its superior corrosion resistance and high strength.
| Cr | Ni | P | S | Mo | Mn | Si | C |
|---|---|---|---|---|---|---|---|
| 18.00 – 20.00 | 11.00 – 15.00 | ≤ 0.045 | ≤ 0.030 | 3.00 – 4.00 | ≤ 2.00 | ≤ 1.00 | ≤ 0.08 |
Data source: ASTM A312-25 / ASME SA312 Table 1, TP317 row ≤ heat-analysis acceptance limits. Confirm the values against the ordered edition and the MTC.
Typical Mechanical Properties
Stainless Steel 317 is specifically designed to maintain its strength and shape in high-stress, corrosive environments.
| Tensile Strength | Yield Strength | Elongation | Hardness |
|---|---|---|---|
| ≥ 515 MPa | ≥ 205 MPa | ≥ 35% | ≤ 217 HBW |
Note: Typical values for reference only — not acceptance limits. Mechanical properties are reported on the MTC against the ordered standard, product form, condition and test temperature.
Typical Physical Properties
These physical properties highlight the material’s ability to perform reliably under a wide range of conditions.
| Density | Melting Point | Thermal Expansion | Thermal Conductivity | Modulus of Elasticity | Electrical Resistivity |
|---|---|---|---|---|---|
| 8.0 g/cm3 | 1398 -1454 °C | 16.6 μm/m·°C (20-100°C) | 16.3 W/m·K (20°C) | 193 GPa | 0.74 × 10⁻⁶ Ω·m (20°C) |
Note: Typical values for reference only — not acceptance limits. Physical and mechanical properties are reported on the MTC against the ordered standard, product form and condition.
Size Tolerance Chart (mm)
| NPS Designator (Inches) | Permissible Variations in Outside Diameter (Inches) |
| 1⁄8 to 1 1⁄2, inclusive | Over: 1⁄64 in. (0.015 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 1 1⁄2 to 4, inclusive | Over: 1⁄32 in. (0.031 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 4 to 8, inclusive | Over: 1⁄16 in. (0.062 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 8 to 18, inclusive | Over: 3⁄32 in. (0.093 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 18 to 26, inclusive | Over: 1⁄8 in. (0.125 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 26 to 34, inclusive | Over: 5⁄32 in. (0.156 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 34 to 48, inclusive | Over: 3⁄16 in. (0.187 in.) |
| Under: 1⁄32 in. (0.031 in.) |
Tolerance basis: permitted variations per the governing specification stated on this page and the applicable general-requirements standard (ASTM A999 / ASME SA999) for the ordered product form; the wall-thickness and length variations in this section follow the same basis.
The wall thickness tolerances are defined by the nominal wall thickness (t) and the outside diameter (D).
1. Minimum Wall Thickness
The minimum wall thickness at any point on the pipe shall not be more than {12.5%} under the nominal (specified) wall thickness.
2. Maximum Wall Thickness (Percentage Over Nominal)
The maximum allowable wall thickness variation depends on the size and the t/D ratio (ratio of nominal wall thickness to ordered outside diameter):
| NPS Designator (Inches) | t/D Ratio | Permissible Variation (Over Nominal WT) |
| 1/8 to 2, inclusive | All ratios | +20.0% |
| 3 to 18, inclusive | t/D ≤ 5% | +22.5% |
| 3 to 18, inclusive | t/D >5% | +15.0% |
| 20 and larger (Seamless) | t/D ≤ 5% | +22.5% |
| 20 and larger (Seamless) | t/D >5% | +15.0% |
| 20 and larger (Welded) | All ratios | +17.5% |
For pipe ordered to a Specific Cut Length, the standard tolerance is +1⁄8 in. [3.2 mm], -0 in. [0 mm].
Pipe is typically supplied in Single Random Lengths (17 to 24 ft) or Double Random Lengths (38 to 40 ft), unless otherwise specified.
Disclaimer: These tolerances are based on ASTM A999/A999M general dimensional requirements commonly referenced by ASTM A312 and ASTM A790. The full and most current specification document must always be consulted for official design and procurement purposes.
Common Industrial Applications
TP317 seamless stainless steel pipes are widely used in:
Chemical & Petrochemical Industry
- Acid transport systems
- Reactors and pressure vessels
Pulp & Paper Industry
- Bleaching equipment
- Sulfite liquor handling
Marine & Offshore Engineering
- Seawater cooling systems
- Desalination plants
Textile Industry
- Dyeing and chemical treatment systems
Food & Beverage Industry
- Acidic processing pipelines
- Hygienic fluid transfer systems
Quality Assurance & Inspection
Inspection Procedures
The scope below is applied as specified on the purchase order.
Non-Destructive Testing (NDT)
- PMI (Positive Material Identification), when specified
- Eddy Current Testing (ET)
- Ultrasonic Testing (UT)
- Hydrostatic Pressure Testing
Mechanical Testing
- Flattening Test
- Flaring Test
- Hardness Test
Corrosion Testing
- Intergranular Corrosion (IGC) Test
- Pitting Resistance Test
Frequently Asked Questions
What sizes are available for TP317 seamless pipe?
The overall range is OD 6–1016 mm; WT 0.5–65 mm. Requirements outside this range are reviewed against mill capability on request.
Which specification governs TP317 seamless pipe?
ASTM A312 / ASME SA312 is the governing specification for TP317 seamless pipe. The edition in force at order time is stated on the quotation and purchase order; chemistry, mechanical properties, heat treatment, dimensions and testing are reported against the ordered standard and material heat.
What inspection documents are provided?
Each order is documented with a mill test certificate stating heat chemistry and mechanical test results. EN 10204 3.1 certification, hydrostatic testing, eddy-current or ultrasonic inspection and PMI are performed when specified in the purchase order.
Technical review: page data reviewed by the Xinzhe technical desk on 2026-09-27. Chemistry acceptance limits are compiled from the governing ASTM/ASME specification stated on this page; mechanical and physical values are typical reference data and are not acceptance guarantees. Values must be confirmed against the standard edition in force at order time and the material test certificate.
Ready to Request a Quotation?
Send the NPS and schedule (or actual OD and wall), quantity, length, end finish and the inspection items you need as acceptance criteria — you will get a written quotation stating the specification and edition, delivery condition, documents included and lead time.
For the same grade in tube form, see the TP317 seamless tube. To compare other grades and size combinations, browse the Stainless Steel Seamless Tube category. Minimum order quantity and lead time are confirmed on enquiry against the ordered grade, size and quantity.
