ASTM A213 TP347H Seamless Steel Tube
High-Temperature Stabilized Stainless Steel Tubes for Boilers & Heat Exchangers
ASTM A213 TP347H seamless steel tubes are high-carbon, niobium-stabilized austenitic stainless steel tubes specifically designed for high-temperature and high-pressure service. Manufactured in accordance with ASTM A213, TP347H tubes provide excellent resistance to intergranular corrosion, oxidation, and creep,Widely used for boilers, superheaters, heat exchangers, and pressure equipment operating at elevated temperatures.
TP347H is widely specified in power plants, refineries, petrochemical facilities, and thermal processing industries where long-term strength and structural stability are critical.
What Is ASTM A213?
ASTM A213 is the standard specification for seamless ferritic and austenitic alloy-steel boiler, superheater, and heat exchanger tubes.
Download ASTM A213 standard in PDF
Material Grade: TP347H Stainless Steel
TP347H is the high-carbon version of TP347, alloyed with niobium (Nb) to stabilize carbon and prevent chromium carbide precipitation during high-temperature exposure.
Product Form & Manufacturing
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Product Type: Seamless stainless steel tube
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Manufacturing Process: Hot finished / cold drawn
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Delivery Condition: Solution annealed
Size Range & Specifications
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Outside Diameter: 6.35 mm – 114.3 mm (1/4″ – 4-1/2″)
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Wall Thickness: 0.5 mm – 12.7 mm
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Length: Random length or fixed length
Chemical Composition – TP347H (Typical, wt %)
| Grade | UNS Designation | Carbon | Manganese | Phosphorus | Sulfur | Silicon | Chromium | Nickel | Molybdenum | Nitrogen | Niobium | Titanium | Other Elements |
| TP347H | S34709 | 0.04–0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0–19.0 | 9.0–13.0 | 8×C–1.10 |
Mechanical Properties (Room Temperature – Typical)
| Grade | UNS Designation | Tensile Strength min ksi [MPa] | Yield Strength min ksi [MPa] | Elongation % | Brinell/Vickers | Rockwell |
| TP347H | S34709 | 75 [515] | 30 [205] | 35 | 192 HBW / 200 HV | 90 HRB |
(TP347H offers significantly improved creep strength at elevated temperatures compared to TP347)
Heat Treatment
ASTM A213 TP347H seamless tubes are supplied in the solution annealed condition, ensuring optimal corrosion resistance and a stable austenitic structure for high-temperature service.
Testing & Inspection
ASTM A213 TP347H tubes undergo comprehensive quality control, including:
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Chemical analysis
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Tensile testing
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Flattening and flaring tests
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Eddy current or hydrostatic testing
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Dimensional inspection
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Visual and surface inspection
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Certification: EN 10204 3.1 / ASME MTR
Applications of ASTM A213 TP347H Seamless Tubes
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Boilers and superheaters
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Heat exchangers and condensers
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Power generation plants
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Oil refineries and petrochemical units
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High-temperature steam and process piping
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Pressure vessels and thermal systems
TP347H vs TP321H Tubes
| Item | TP321H | TP347H |
|---|---|---|
| Stabilizing Element | Titanium (Ti) | Niobium (Nb) |
| Creep Resistance | Very Good | Excellent |
| High-Temp Strength | Very Good | Superior |
| Typical Use | High-temp piping | Severe high-temp service |
ASTM-A213-SA213-TP347H-Seamless-Steel-tube
ASTM A213 TP347H Seamless Steel tube
ASTM A213 TP347H seamless steel tubes deliver outstanding high-temperature strength, resistance to intergranular corrosion, and long-term reliability for boiler, superheater, and heat exchanger applications. Fully compliant with ASTM A213 and ASME requirements, TP347H tubes are a trusted solution for power plants, refineries, and critical thermal systems.
