ASME SA312 TP347 347H PIPE Manufacturer
ASTM A312: Specification for seamless, welded, and heavily cold-worked austenitic stainless steel pipes for high-temperature and corrosive environments.
TP347: A stabilized stainless steel alloy — basically Type 304 + Columbium (Niobium).
Tp347 is an austenitic stainless steel stabilized with columbium. The addition of columbium makes this stainless grade perfect performance at high oxidation condition under high temperatures at around 800 degrees Celsius
TP347H (UNS S3409) is the stainless steel grade of TP347 with a higher carbon content(0.04 – 0.10)
347H has good resistance to intergranular corrosion, and has good corrosion resistance in alkali, seawater and a variety of acid solutions. Due to its good heat resistance and oxidation resistance, it can withstand small loads at temperatures below 850 degrees.
Other Product also available in 347/347H grade
A182 F347/347H Flanges
A403 WP347/347H Pipe fittings
ASME SA312 TP347/347H Pipe specfication
- Size Range: NPS 1/8″ to 30″
- Wall Thickness: Schedules 5S to XXS
- Dimension Standard:ASME B36.19, Tolerance to ASTM A999
- Ends: Plain End (PE), Beveled End (BE)
Chemical compostion of TP347/347H
| Element | TP347 (%) | TP347H (%) |
|---|---|---|
| Carbon (C) | ≤ 0.08 | 0.04 – 0.10 |
| Manganese (Mn) | ≤ 2.00 | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 | ≤ 0.030 |
| Silicon (Si) | ≤ 1.00 | ≤ 1.00 |
| Chromium (Cr) | 17.0 – 19.0 | 17.0 – 19.0 |
| Nickel (Ni) | 9.0 – 13.0 | 9.0 – 13.0 |
| Niobium (Cb/Ta) | ≥ 10xC (approx. 0.3–1.0) | ≥ 10xC (approx. 0.3–1.0) |
Mechanical Property of TP347/347H
TP347 and TP347H share the same mechanical properties according to ASTM A312
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | ≥ 75 ksi (515 MPa) |
| Yield Strength (0.2%) | ≥ 30 ksi (205 MPa) |
| Elongation (%) | ≥ 35% (in 2 inches) |
| Hardness (HRB) | ≤ 90 |
ASTM A312 Tp347/347H Pipe Heat Treating Condition
The annealing temperature range for TP347 is upt 1900°F (1040°C). While the primary purpose of annealing is to obtain softness and high ductility
Testing & Inspection Requirements of stainless steel pipes
- Hydrostatic Test or Nondestructive Examination (NDE)
- Tensile & Flattening Tests
- Visual & Dimensional Inspection
- PMI (Positive Material Identification)
Applications of TP347/347H
- Heat exchangers and boilers
- High-temperature chemical processing
- Superheaters and reheater tubing in power plants
- Refineries and high-pressure steam systems
- Piping systems exposed to high temps and corrosive fluids
Character of TP 347 or TP 347H
| Property | Details |
|---|---|
| Corrosion Resistance | Excellent, even after welding |
| Temperature Resistance | Very good for high-temp service (up to ~870°C) |
| Weldability | Good — doesn’t require post-weld heat treatment |
| Creep Strength | Better than 304/316 at high temps |
| Formability | Slightly less than 304/316 but still workable |
which grade to select TP 347 or TP 347H?
Basically,TP347 and TP347H share almost the same application because they have very similar compostion.Mechnical Properies.
However,there are some differences between this 2 grades.Here is the thing you need to know to select the right grade.
Select TP347 grade,for better weldability and less risk of sensitization. because of Lower carbon content
Select TP347H grade ,347H has higher carbon content,347H is more resistant to thermal fatigue and long-term deformation. improved creep strength and grain stability.operating temp ≥ 550°C (1022°F) or long exposure at high temps
