LTCS A333 Gr 6 welded pipe description
A333 Gr.6 steel pipe is a low-temperature seamless steel pipe conforming to the ASTM A333 standard, primarily used in extreme low-temperature environments ranging from -45°C to -101°C. Its core material is carbon steel or low-alloy steel, with elements such as nickel (Ni) added to enhance its low-temperature toughness. The ASTM A333 standard clearly specifies its chemical composition, mechanical properties, and impact testing requirements, ensuring high strength and resistance to brittle fracture even at low temperatures. A333 Gr.6 low-temperature steel pipe plays a vital role in multiple fields, particularly in the petrochemical industry, where it is widely used in the production processes of ethylene, polypropylene, synthetic ammonia, and LPG.
A333 gr6 Carbon Steel Low temperature tube specification
Chemical Properties
| Carbon | Silicon | Manganese | Phosphorous | Sulphur | Molybdenum | Nickel | Chromium | Copper | Others |
|---|---|---|---|---|---|---|---|---|---|
| max 0.30 | min 0.10 | 0.29 – 1.06 | 0.025 | 0.025 | – | – | – | – | – |
Mechanical Properties
| Yield Strength | Tensile Strength | Elongation A5 min | |||
|---|---|---|---|---|---|
| MPa min | ksi min | MPa min | MPa min | ksi min | Percentage |
| 415 | – | 60 | 30 | ||
Equivalent Designation
| DIN | EN | BS | NFA | ASTM | ASME |
|---|---|---|---|---|---|
| DIN 17178 Grade FGP 28 | EN P215NL Grade 10216-4 | NFA A 36-2051) Grade A 42 AP | ASTM A333 Grade6 | ASME SA 333 Grade 6 | UNI C20 |
SA333 GR3 V.S. SA333 GR6
1. Temperature Suitability
| Aspect | SA333 GR.3 | SA333 GR.6 |
|---|---|---|
| Minimum Service Temperature | -150°F (-101°C) | -50°F (-45°C) or colder (depending on thickness/testing) |
| Typical Applications | Ultra-low-temperature environments (e.g., liquid nitrogen systems) | Standard low-temperature service (e.g., LNG, arctic pipelines) |
2. Material Composition & Processing
| Aspect | SA333 GR.3 | SA333 GR.6 |
|---|---|---|
| Heat Treatment | Quenched and tempered or normalized | Normalized (refined grain structure for toughness) |
| Chemical Composition | Similar carbon-manganese steel, but GR.3 may have tighter controls for ultra-low-temp use | Controlled impurities (S, P) to enhance low-temp ductility |
3. Mechanical Properties
| Aspect | SA333 GR.3 | SA333 GR.6 |
|---|---|---|
| Tensile Strength | ~550–720 MPa (varies by thickness) | ~485 MPa (70,000 psi) min |
| Yield Strength | Higher than GR.6 (exact values depend on thickness) | ~275 MPa (40,000 psi) min |
| Impact Toughness | Superior at -150°F (-101°C) due to specialized processing | Excellent at -50°F (-45°C) with mandatory impact testing |
4. Testing Requirements
| Aspect | SA333 GR.3 | SA333 GR.6 |
|---|---|---|
| Impact Testing | Required at -150°F (-101°C) or colder | Required at -50°F (-45°C) or as specified |
| Energy Absorption | Higher minimums to ensure performance at extreme cold | Standardized minimums (e.g., 20 ft·lbf/27 J at -50°F) |
5. Applications
| Aspect | SA333 GR.3 | SA333 GR.6 |
|---|---|---|
| Common Uses | - Liquid nitrogen storage/transfer - Aerospace cryogenic systems - Ultra-cold industrial processes |
- LNG pipelines and terminals - Arctic oil/gas exploration - Refrigeration plants |
6. Cost & Availability
| Aspect | SA333 GR.3 | SA333 GR.6 |
|---|---|---|
| Cost | Higher (due to specialized processing and testing for extreme cold) | Lower (more common for standard low-temp apps) |
| Availability | Limited to specialized suppliers | Widely available in standard pipe sizes |
7. Key Standards
| Aspect | SA333 GR.3 | SA333 GR.6 |
|---|---|---|
| Specification | ASTM A333/ASME SA333 | ASTM A333/ASME SA333 |
| Grade Designation | GR.3 for ultra-low-temperature service | GR.6 for general low-temperature service |
Applications of A333 Gr.6:
1. Liquefied Natural Gas (LNG) Equipment: Used in pipelines and storage tanks, as it maintains its performance at extremely low temperatures of -162°C (requires insulation).
2. Chemical Industry: Suitable for transporting cryogenic media such as ammonia and ethylene.
3. Refrigeration Systems: Such as large cold storage facilities or cryogenic reactors.
Test and inspection
Packaging and shipping
