Product Overview – ASTM A312 TP347 Seamless Pipes
ASTM A312 TP347 is an austenitic stainless steel grade stabilized with niobium (also known as columbium). The addition of niobium prevents chromium carbide precipitation during welding and high temperature exposure.
Compared to 321, TP347 offers improved resistance to stress rupture and creep, making it suitable for demanding refinery and petrochemical environments.
The seamless construction enhances pressure-bearing capability and structural uniformity in critical process piping.
Standard & International Identification -ASTM A312 TP347 Seamless Pipes
ASTM A312 TP347 Seamless Pipe Specifications
| Manufacturing Type : | Seamless |
| Available Sizes: | 1/8″ NB to 24″ NB |
| Schedules: | 5S, 10S, 40S, 80S, 160, XS, XXS |
| Length: | 6m, 12m, Custom Length |
| End Type : | Plain End (PE), Beveled End (BE) |
| Testing : | Hydrostatic, Ultrasonic, PMI Testing |
| Certification : | EN 10204 3.1 / 3.2 MTC |
| Dimensional compliance: | ASME B36.19M. |
All specifications are in accordance of ASTM A312 / ASME SA312 standards. Mechanical and chemical values are as per standard limits. Mill Test Certificates (MTC) available upon request.
Chemical Composition of ASTM A312 TP347 Seamless Pipe
(As per ASTM specification)
| Element | Max (%) |
|---|---|
| Carbon (C) | 0.08% |
| Manganese (Mn) | 2.00 % |
| Silicon (Si) | 1.00 % |
| Phosphorus (P) | 0.045 % |
| Sulfur (S) | 0.030 % |
| Chromium (Cr) | 17.0 – 19.0 % |
| Nickel (Ni) | 9.0 – 13.0% |
| Niobium (Nb + Ta): | 10 × Carbon content (min) |
| Iron (Fe) | Balance |
Note: Niobium stabilizes the structure and enhances high-temperature performance.
Mechanical Properties of TP347 Seamless Pipes
| Property | Minimum Value |
|---|---|
| Tensile Strength | ≥ 515 MPa |
| Yield Strength | ≥ 205 MPa |
| Elongation | ≥ 35% |
Designed for improved creep and stress rupture resistance compared to non-stabilized grades.
Performance Advantages of SS 347 Seamless Pipes
SS 347 seamless pipes offer:
For long-term elevated temperature service in ASME pressure systems, TP347 is often specified.
Applications of ASTM A312 TP347 Seamless Pipes
- 🔸Superheater and reheater systems
- 🔸Petrochemical processing units
- 🔸Power generation plants
- 🔸Pressure vessels
- 🔸Oil & gas refineries
- 🔸Thermal processing equipment
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