Product Description
Seamless Stainless Steel Pipe Size: Outside Diameter: 21.3mm – 610mm (1/2″ – 24″), Wall Thickness: 0.5mm – 50mm (Schedule 5S, 10S, 40S, 80S, 160, XXS), Length: 6m – 12m standard, custom lengths up to 18m
Standard & Grade of Seamless Stainless Steel Pipe: ASTM A312 TP309S, TP309H; also ASME SA312; EN 10216-5 1.4828; Equivalent to AISI 309S, 309H
Usage of Seamless Stainless Steel Pipe: Furnace radiant tubes and retorts, heat treatment furnace baskets and fixtures, thermal oxidizers and incinerators, cement kiln riser ducts and cooler tubes, catalytic converter housings, annealing and sintering furnace components, glass handling equipment, power plant ducting (high temperature), high-temperature chemical reactors, refinery heater tubes (moderate chromium service)
Womic Steel offering high quality & competitive prices of ASTM A312 TP309S/TP309H seamless stainless steel pipe, high temperature seamless tube, oxidation resistant seamless pipe, SMLS stainless pipe, heat resistant seamless tube. Mill certificate EN 10204 3.1/3.2, hydro test, UT/ET, solution annealed, beveled/plain ends, pickled finish available. Factory direct supply for heat treatment, furnace, and high-temperature industrial projects worldwide.
Womic Steel: Manufacturing Capabilities & Company Strength
Womic Steel Group is a premier manufacturer and global exporter with over 20 years of expertise in producing high-temperature stainless steel seamless tubular products. Our state-of-the-art seamless pipe production facility utilizes advanced hot-rolling and cold-drawing processes specifically optimized for high-chromium grades:
Cold Drawn (CD) Seamless Line: For diameters from 21.3mm to 219.1mm (1/2″ – 8″), wall thickness from 1.0mm to 25mm. Cold drawing provides superior dimensional accuracy, excellent surface finish, and uniform grain structure – critical for high-temperature creep resistance. Preferred for smaller diameter furnace tubes and thermowells.
Hot Finished (HF) Seamless Line: For diameters from 114.3mm to 610mm (4″ – 24″), wall thickness from 4.0mm to 50mm. Hot rolling process produces heavy wall pipes for large diameter high-temperature headers and furnace coils.
Extrusion Line (upon request): For diameters up to 914mm (36″) for special project applications.
All seamless stainless steel pipes undergo solution annealing (heat treatment) at 1040-1120°C followed by water quenching to dissolve carbides and restore high-temperature properties, followed by pickling and passivation.
Quality Certifications & Regulatory Compliance:
ISO 9001:2015 Certified
PED 2014/68/EU (CE Marking) for pressure equipment
EN 10204 3.2 Certification with third-party validation (TÜV, BV, SGS, LR)
Third-Party Inspection (TPI) approved by SGS, BV, ABS, DNV, TÜV
ASME Boiler and Pressure Vessel Code (Section I, VIII) compliance
Production Flexibility:
Cold Drawn: 21.3–219.1mm OD × 1.0–25mm WT × ≤ 12m
Hot Finished: 114.3–610mm OD × 4.0–50mm WT × ≤ 12m
Finishing options: Annealed and pickled, bright annealed (for small sizes)
ASTM A312 TP309S / TP309H: Material Composition & Performance Characteristics
ASTM A312 TP309 is an austenitic stainless steel with higher chromium (23%) and nickel (13%) than 304, providing superior oxidation resistance at elevated temperatures up to 1000°C. TP309S is the low carbon version (≤ 0.08% C) for general high-temperature service where welding is required. TP309H has higher carbon (0.04-0.10%) for enhanced creep strength at high temperatures.
Chemical Composition (Ladle Analysis, % by mass):
| Element | TP309S (ASTM A312) | TP309H (ASTM A312) |
| C | ≤ 0.08 | 0.04 – 0.10 |
| Mn | ≤ 2.00 | ≤ 2.00 |
| P | ≤ 0.045 | ≤ 0.045 |
| S | ≤ 0.030 | ≤ 0.030 |
| Si | ≤ 1.00 | ≤ 1.00 |
| Cr | 22.0 – 24.0 | 22.0 – 24.0 |
| Ni | 12.0 – 15.0 | 12.0 – 15.0 |
| N | ≤ 0.10 | ≤ 0.10 |
Mechanical Properties (Room Temperature, Solution Annealed):
| Property | TP309S | TP309H |
| Yield Strength (min, 0.2% offset) | 205 MPa (30,000 psi) | 205 MPa (30,000 psi) |
| Tensile Strength (min) | 515 MPa (74,700 psi) | 515 MPa (74,700 psi) |
| Elongation (min, 50mm gauge) | 35% | 35% |
| Hardness (max) | 90 HRB | 90 HRB |
Physical Properties:
Density: 7.98 g/cm³
Modulus of Elasticity: 200 GPa (29 × 10⁶ psi) at room temperature
Thermal Conductivity: 15.0 W/m·K at 100°C
Coefficient of Thermal Expansion: 15.0 × 10⁻⁶/°C (20-100°C)
High-Temperature Properties:
Maximum continuous service temperature in air: 1000°C (1830°F) for TP309S
Scaling resistance: Excellent up to 1000°C due to high chromium (23%)
Creep strength at 800°C: Higher for TP309H (0.04-0.10% C) than TP309S
Oxidation resistance in air: Excellent; sulfidation resistance: Good (better than 304)
Comparison with 304 and 310:
TP309 has higher chromium (23%) than 304 (18%), providing better oxidation resistance (1000°C vs 850°C)
TP309 has higher nickel (13%) than 304 (8%), providing better carburization resistance
TP310 (25% Cr, 20% Ni) has even higher oxidation resistance (1100°C) but higher cost
TP309 is often chosen as a cost-effective alternative to 310 for service up to 1000°C
Dimensional Range & Standards Compliance
| Item | Specification |
| Standard | ASTM A312 / ASME SA312 (also A213, A269, A999) |
| Manufacturing Processes | Cold Drawn (CD), Hot Finished (HF) |
| Outside Diameter Range | 21.3mm – 610mm (1/2″ – 24″) |
| Wall Thickness Range | 0.5mm – 50mm (Schedule 5S, 10S, 40S, 80S, 160, XXS) |
| Length Range | Standard: 6m; Extended: 12m, 18m, up to 18m |
| End Finish | Plain End (PE), Beveled End (BE) |
| Surface Finish | Annealed & Pickled, Bright Annealed |
| Tolerances (per ASTM A999) | OD: ±0.5% or ±3.2mm; WT: ±12.5% (OD < 4″) / ±15% (OD ≥ 4″); Length: +50mm / -0mm |
| Straightness | ≤ 0.2% of total length (cold drawn); ≤ 0.25% (hot finished) |
Available Dimensions & Specifications – ASTM A312 TP309S/309H Seamless Stainless Steel Pipe (Selected Typical Sizes)
| NPS | OD (mm) | Schedule | WT (mm) | Weight (kg/m) | Process | Standard Length | Typical Application |
| 1/2″ | 21.3 | 40S | 2.77 | 1.27 | CD | 6m | Thermowell |
| 3/4″ | 26.7 | 40S | 2.87 | 1.69 | CD | 6m | Instrument line |
| 1″ | 33.4 | 40S | 3.38 | 2.50 | CD | 6m | Pilot tube |
| 1-1/2″ | 48.3 | 40S | 3.68 | 4.05 | CD | 6m | Burner line |
| 2″ | 60.3 | 40S | 3.91 | 5.44 | CD | 6m / 12m | Heater tube |
| 3″ | 88.9 | 40S | 5.49 | 11.3 | CD/HF | 6m / 12m | Radiant tube |
| 4″ | 114.3 | 40S | 6.02 | 16.1 | CD/HF | 6m / 12m | Furnace coil |
| 6″ | 168.3 | 40S | 7.11 | 28.3 | HF | 6m / 12m | Transfer line |
| 8″ | 219.1 | 40S | 8.18 | 42.6 | HF | 12m | Thermal oxidizer |
| 10″ | 273.0 | 40S | 9.27 | 60.3 | HF | 12m | Hot gas duct |
| 12″ | 323.9 | 40S | 10.31 | 79.8 | HF | 12m | Main header |
| 16″ | 406.4 | 40S | 12.70 | 123.4 | HF | 12m | Cement cooler |
Custom dimensions outside these ranges available. TP309H recommended for creep service above 650°C; TP309S for welded applications without PWHT.
Common Seamless High-Temperature Stainless Steel Standards & Grades Manufactured by Womic Steel
| Standard | Steel Grades | Typical Application | Manufacturing Process |
| ASTM A312 | TP309S, TP309H, TP310S, TP310H, TP304H, TP316H | High temperature, oxidation resistant | CD/HF |
| ASTM A213 | TP309S, TP309H, TP310S | Boiler, superheater, heat exchanger tubes | CD |
| ASTM A269 | TP309S | General service tubing | CD |
| EN 10216-5 | 1.4828 (309) | Pressure purposes, high temp | CD/HF |
Usage: Furnace radiant tubes, heat treatment baskets, thermal oxidizers, cement kilns, catalytic converters, annealing covers, high-temperature chemical reactors.
Manufacturing Process – Seamless Stainless Steel Pipe (Cold Drawn / Hot Finished)
Womic Steel employs two primary seamless manufacturing processes for TP309S/309H production.
Cold Drawn (CD) Process – Small to Medium Diameter (21.3–219.1mm OD):
Raw Material (Billet) Inspection: Billet verified for TP309S composition (Cr 22-24%, Ni 12-15%, C ≤ 0.08% or 0.04-0.10% for H).
Billet Preparation: Cut to length, center-drilled, heated to 1150-1250°C.
Piercing / Rotary Forging: Heated billet pierced to create hollow shell.
Hot Rolling: Hollow shell rolled over mandrel to intermediate dimensions.
Pickling: Scale removal before cold drawing.
Cold Drawing (Multiple Passes): Drawn through die with floating plug to final dimensions. Multiple passes with intermediate annealing for heavy reductions.
Solution Annealing: 1040-1120°C, water quench. Critical for dissolving carbides.
Straightening & Cut to Length
Pickling & Passivation
NDT: Eddy current (100%) + hydrostatic test.
Final Inspection & Marking
Hot Finished (HF) Process – Medium to Large Diameter (114.3–610mm OD):
Billet Heating: 1200-1280°C
Piercing
Continuous Rolling (Mandrel Mill)
Sizing Mill
Solution Annealing: 1040-1120°C, water quench.
Pickling & Passivation
NDT & Hydrostatic Test
Final Inspection & Marking
Special Considerations for TP309H:
Higher carbon (0.04-0.10%) provides higher creep strength
Must be solution annealed to avoid carbide precipitation
TP309S (≤ 0.08% C) preferred for welded applications without PWHT
Quality Control & Testing Procedures for ASTM A312 TP309S/309H Seamless Stainless Steel Pipe
| Stage | Inspection Method | Purpose |
| Raw Material | Chemical Analysis (OES) | Verify TP309S (Cr 22-24%, Ni 12-15%) |
| Raw Material | Tensile Testing | Yield ≥ 205 MPa, Tensile ≥ 515 MPa |
| Raw Material | Elevated Temperature Tensile (if specified) | Verify strength at service temperature |
| After Solution Annealing | Hardness Test | ≤ 90 HRB |
| Finished Pipe | Hydrostatic Test (Mandatory) | Pressure integrity – 85-100% SMYS |
| Finished Pipe | Eddy Current Test (100%) | Surface/near-surface defects |
| Finished Pipe | Flattening / Flaring Test | Ductility |
| Finished Pipe | PMI | Confirm grade (Cr, Ni) |
| Finished Pipe | Intergranular Corrosion Test (A262 Practice E) | Detect sensitization (if specified) |
| Finished Pipe | Visual & Marking | Traceability |
Optional for High-Temperature Service:
Elevated temperature tensile test (e.g., at 800°C)
Oxidation test (weight gain after exposure)
Creep rupture test (for TP309H)
Grain size measurement (ASTM E112)
Packaging & Shipping
Packaging:
Protective Covering: Individual plastic sleeves or spiral wrapping applied to each tube to prevent surface scratches and moisture contact.
Bundling: Tubes bundled together and secured with steel straps (3-5 straps per bundle) with protective corner guards. Wooden dunnage or foam rings between layers prevents abrasion.
End Caps: Plastic end caps (PE or PP) on both ends protect beveled/plain ends and threads from impact damage and debris ingress.
Wooden Crates: For high-value or precision orders, tubes packed in sturdy wooden crates or plywood cases for enhanced protection.
Desiccant Bags: Added for moisture-sensitive applications or long sea freight.
Shipping:
Mode of Transportation: Container vessels (20ft/40ft), bulk carriers (>500 tons), or air freight for sample shipments.
Containerization: Tubes loaded into standard containers. Max load: 20-25 tons per 20ft, 25-28 tons per 40ft.
Bulk Vessel Loading: Large orders loaded directly into bulk carriers with lifting beams, dunnage, and lashing to secure cargo.
Labeling & Documentation: Each bundle labeled with grade, standard, dimensions, heat number. Complete shipping documents (invoice, packing list, bill of lading, COO, MTC) prepared for customs clearance.
Secure Fastening: Bundles secured with steel strapping, dunnage bags, or timber bracing to prevent shifting during transit.
Tracking & Insurance: Container tracking numbers provided. Marine cargo insurance available upon request.
Primary Applications – ASTM A312 TP309S/309H Seamless Stainless Steel Pipe
Furnace radiant tubes and retorts: Direct-flame exposure in heat treating furnaces (annealing, hardening, brazing). TP309 resists oxidation at 1000°C.
Heat treatment furnace baskets and fixtures: Supporting parts during heat treatment cycles (repeated heating/cooling). TP309H provides creep strength.
Thermal oxidizers and incinerators: Ducting and stacks handling hot combustion gases (800-1000°C) from chemical and waste streams.
Cement kiln components: Riser ducts, cooler tubes, and preheater cyclones exposed to hot cement dust and gases.
Catalytic converter housings: Automotive and industrial catalytic systems operating at 800-950°C.
Annealing and sintering furnace covers: Protective covers for annealing operations in metal processing.
Glass handling equipment: Rolls and supports in float glass lines (high temperature).
Power plant ducting: High-temperature flue gas ducts in coal-fired plants (where 304 is insufficient).
High-temperature chemical reactors: Process piping at 700-900°C.
Packaging & Shipping – ASTM A312 TP309S/309H Seamless Stainless Steel Pipe
Packaging:
Anti-corrosion protection: VCI paper or plastic wrap. For high-temperature service, no oil residue.
End caps: Plastic caps for beveled ends.
Bundling (Small diameters): Bundles with steel straps and interleaving paper.
Individual packaging (Large diameters): Plastic film wrap.
Wooden crates for critical high-temperature applications.
Shipping:
Containers for ≤ 610mm, break-bulk for larger diameters.
Documentation: MTC 3.1/3.2, hydrotest report, eddy current/UT reports, PMI report, dimensional report, packing list, COO. Optional high-temperature test reports upon request.
Womic Steel Advantages & FAQ – ASTM A312 TP309S/309H Seamless Stainless Steel Pipe
Why Partner with Womic Steel for TP309S/309H Seamless Pipe?
Complete Size Range: Cold Drawn 1/2″ – 8″, Hot Finished 4″ – 24″.
Full solution annealing (1040-1120°C, water quench).
TP309H available for creep-critical high-temperature service.
Elevated temperature tensile and creep testing available.
Competitive lead times: 25-35 days for CD, 35-50 days for HF.
Global Certification: ISO 9001, PED (CE), EN 10204 Type 3.2.
Frequently Asked Questions (FAQ) – ASTM A312 TP309S/309H Seamless Stainless Steel Pipe
Q: What is the difference between TP309S and TP309H?
A: TP309S has low carbon (≤ 0.08%) for better weldability and resistance to intergranular corrosion in as-welded condition. TP309H has higher carbon (0.04-0.10%) for enhanced creep strength at elevated temperatures (above 650°C). For continuous high-temperature service under stress (e.g., radiant tubes, creep-critical), choose TP309H. For cyclic service or where post-weld heat treatment is not possible, TP309S is acceptable.
Q: What is the maximum service temperature for TP309?
A: TP309 is suitable for continuous service in air up to 1000°C (1830°F) with good oxidation resistance. For intermittent service, it can withstand up to 1035°C. Above 1000°C, scaling increases; TP310 (25Cr-20Ni) is recommended for 1100°C service.
Q: How does TP309 compare to TP304 for high-temperature service?
A: TP309 has higher chromium (23% vs 18%) and nickel (13% vs 8%), providing significantly better oxidation resistance (up to 1000°C vs 850°C for 304). TP309 also has better carburization and sulfidation resistance. For service above 850°C, TP309 is preferred.
Q: Is TP309H necessary for radiant tubes in heat treating furnaces?
A: For radiant tubes operating above 650°C under stress (creep conditions), TP309H is recommended because its higher carbon content provides higher creep rupture strength. For lower stress applications (e.g., heat baskets, fixtures), TP309S is acceptable.
Q: Does TP309 require solution annealing after processing?
A: ASTM A312 requires solution annealing for seamless pipe. For TP309S, solution annealing is required to meet mechanical properties and corrosion resistance. Womic performs solution annealing on all TP309 seamless pipes.
Q: What is the typical lead time for TP309 seamless pipe?
A: 25-35 days for CD (small to medium diameters), 35-50 days for HF (large diameters). TP309H may have slightly longer lead times due to specialty billet sourcing.
Q: Can TP309 be used for sulfuric or hydrochloric acid service?
A: No. TP309 is not designed for acid service; it is a high-temperature alloy. For acid service at room temperature, use 304L, 316L, or duplex. TP309 is for oxidation resistance at high temperatures, not for chemical corrosion resistance at low temperatures.
Project Reference – Cement Plant Riser Duct & Cooler Tube Replacement (Vietnam)
Country: Vietnam (Ha Nam province)
Standard & Grade: ASTM A312 TP309H (seamless)
Dimensions & Quantity:
OD 168.3mm (6″) × Schedule 80 (10.97mm WT) – 500 meters (approx. 15 tons) – Hot Finished
OD 219.1mm (8″) × Schedule 80 (12.70mm WT) – 200 meters (approx. 10 tons) – Hot Finished
OD 88.9mm (3″) × Schedule 40 (5.49mm WT) – 400 meters (approx. 3.5 tons) – Cold Drawn
Total: 1,100 meters, approx. 28.5 tons
Specifications: ASTM A312 TP309H seamless, solution annealed and pickled, beveled ends. Hydrostatic testing. Eddy current (CD) and UT (HF). PMI on every pipe. Mandatory elevated temperature tensile test at 800°C (spec minimum 100 MPa, achieved 130-155 MPa). Oxidation test (air at 950°C for 500h) – weight gain < 0.5 mg/cm². Intergranular corrosion test per ASTM A262 Practice E (pass). Grain size ASTM 6-7. Third-party inspection by TÜV Vietnam.
Application: Replacement of riser duct and grate cooler tubes in a cement plant (clinker production). The riser duct carries hot kiln exhaust gases (850-950°C) containing dust (cement clinker particles) and combustion gases (CO₂, SOx, NOx). Previous 304H piping failed after 3 years due to oxidation scaling, carburization, and creep deformation. TP309H was selected for its higher chromium (23%) providing better oxidation resistance up to 1000°C and superior creep strength.
Technical Challenges & Solutions:
Oxidation and carburization at 850-950°C – TP304H (18% Cr) scales rapidly above 850°C. TP309H with 23% Cr forms a more stable Cr₂O₃ scale, resisting oxidation and carburization. Womic performed oxidation test (air at 950°C for 500h): weight gain 0.6 mg/cm² (vs 304H typical 4.5 mg/cm²). Client accepted.
Creep strength at high temperature – Riser duct is under self-weight and thermal expansion stress. TP309H with carbon 0.07-0.09% provided higher creep strength. Elevated temperature tensile at 800°C: yield 135-155 MPa, tensile 210-230 MPa. Creep test (1,000h at 800°C, 35 MPa) – no rupture.
Thermal fatigue resistance – Cement kiln stops/starts cause thermal cycling. TP309H with solution annealed microstructure (fine grain ASTM 6-7) provided good thermal fatigue resistance. No cracking observed after 500 thermal cycles in lab test.
Field welding procedure – Cement plant turnaround schedule limited welding time. Womic provided WPS using GTAW with ER309L filler, preheat 10-20°C, interpass ≤ 150°C, heat input ≤ 1.5 kJ/mm. 15 weld coupons passed RT, PT, and elevated temperature tensile.
Logistics to Ha Nam – Pipes shipped from Shanghai to Haiphong port, then trucked 100km to site. TÜV inspected at port. All 28.5 tons delivered in 2 shipments over 6 weeks. Documentation package accepted without queries.
Result: New TP309H riser duct and cooler tubes installed during 2023 turnaround. After 18 months of operation, inspection showed minimal oxidation (scale thickness < 0.1mm) and no creep deformation or cracking. Client estimates service life 8-10 years (vs 3 years for 304H). Womic Steel is now a preferred supplier for this cement plant's high-temperature alloy needs.
Contact:
Website: www.womicsteel.com
E-mail: sales@womicsteel.com
Tel / WhatsApp / WeChat:
Victor: +86 15575100681
Jack: +86 18390957568
Womic Steel – Your reliable partner for ASTM A312 TP309S/TP309H seamless stainless steel pipes for high-temperature furnace, cement, thermal oxidizer, and heat treatment applications worldwide.
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