Low-temperature Applications
Astm a333 gr.
Low-temperature Applications
Astm a333 gr.6 alloy pipe offers superior low-temperature toughness, corrosion resistance, and durability in cryogenic pipelines, lng systems, and offshore structures.
ASTM A333 Grade 6 Pipe is a seamless and welded carbon steel pipe designed for low-temperature service, offering exceptional notch toughness and corrosion resistance. Conforming to ASTM A333/ASME SA333 standards, this low-temperature pipe is engineered for applications above -45°C (-50°F), with a minimum yield strength of 240 MPa and tensile strength of 415 MPa. Its composition, with a maximum of 0.30% carbon and 0.29-1.06% manganese, ensures durability in harsh environments like oil and gas pipelines, petrochemical plants, and cryogenic systems.
Manufactured through seamless or welding processes without filler metal, the ASTM A333 Grade 6 Pipe undergoes heat treatment (normalizing, quenching, and tempering) to control microstructure, enhancing its impact toughness at low temperatures. Available in sizes from 1/2” to 36” (NPS) with wall thicknesses from 3mm to 12mm (SCH 40 to XXS), and lengths from 3m to 18m, it meets diverse project requirements. Surface treatments such as 3LPE, FBE, or galvanizing improve corrosion resistance, while plain, beveled, or threaded ends facilitate installation in industrial piping systems.
The Seamless Carbon Steel Pipe undergoes rigorous testing, including tensile, impact, hydrostatic, and nondestructive electric tests, to ensure compliance with ASTM A333 standards. Its superior notch toughness, with a minimum Charpy impact value of 18 J at -45°C, makes it ideal for transporting oil, gas, and other fluids in cold environments. The pipe’s ability to resist brittle fracture and withstand cryogenic conditions down to -50°F makes it a preferred choice for applications in refineries, chemical plants, and refrigeration systems.
Compared to other grades like A106, the ASTM A333 Grade 6 Pipe is specifically designed for low-temperature performance, offering enhanced toughness over standard carbon steel pipes. Its versatility extends to structural applications in construction and mechanical engineering, where durability and wear resistance are critical. The pipe’s compatibility with ASTM A350 LF2 flanges and ASTM A420 WPL6 fittings ensures seamless integration into complex industrial piping systems.
The Low Temperature Pipe addresses challenges like pipeline contraction and brittle failure in cold climates, making it a reliable solution for engineers seeking robust industrial piping for extreme conditions. Its high-quality construction and cost-effective performance ensure safety, longevity, and efficiency in demanding applications such as oil and gas transmission and cryogenic equipment fabrication.
| Feature | ASTM A333 Grade 6 | ASTM A106 Grade B | ASTM A335 P9 |
|---|---|---|---|
| Material Type | Carbon Steel | Carbon Steel | Ferritic Alloy Steel |
| Temperature Range | Low (-45°C to ambient) | High (up to 427°C) | High (up to 750°C) |
| Notch Toughness | Superior (18 J at -45°C) | Moderate (Not specified for low temp) | Good (High-temp focus) |
| Corrosion Resistance | Good (With coatings) | Moderate | Excellent (High Cr/Mo) |
| Applications | Oil/Gas, Cryogenic, Chemical | Boilers, Refineries, General Piping | Refineries, Power Plants, Petrochemical |
| Tensile Strength (MPa) | 415 (min) | 415 (min) | 415 (min) |
| Yield Strength (MPa) | 240 (min) | 240 (min) | 205 (min) |
| Key Advantage | Low-temp toughness | General high-temp use | High-temp corrosion resistance |
| Element | Composition (%) |
|---|---|
| Carbon (C) | ≤ 0.30 |
| Manganese (Mn) | 0.29–1.06 |
| Phosphorus (P) | ≤ 0.025 |
| Sulfur (S) | ≤ 0.025 |
| Silicon (Si) | ≥ 0.10 |
| Nickel (Ni) | ≤ 0.40 |
| Chromium (Cr) | ≤ 0.30 |
| Copper (Cu) | ≤ 0.30 |
| Property | Value |
|---|---|
| Tensile Strength | ≥ 415 MPa |
| Yield Strength | ≥ 240 MPa |
| Elongation | ≥ 30 % |
| Impact Toughness | ≥ 27 J @ –100 °C |
| Hardness | ≤ 241 HBW |
| Standard | Pipes | Buttweld Fittings | Forged Steel Fittings | Valves | Bolts and Nuts |
|---|---|---|---|---|---|
| Low Temp Carbon Steel | A333 GR6 | A420 WPL6 | ASTM A350 LF2 | A352 LCB | A320 Gr L7 / A194 Gr 7 |
The equivalent grade to ASTM A333 GR6 is often EN 10216-4 P265NL or DIN 17173 TT St 35N. These grades share similar mechanical properties and are suitable for low-temperature service applications.
ASTM A333
Low temperature pipe refers to pipes specifically designed to withstand and operate effectively in environments with low temperatures, typically below 0°C (32°F).
These pipes are often used in industries such as oil and gas, petrochemicals, and refrigeration, where fluids need to be transported or stored at low temperatures. They are constructed from materials that can maintain their mechanical properties and structural integrity even in extremely cold conditions, ensuring the safe and efficient transportation of fluids. Additionally, low temperature pipes are insulated to prevent heat transfer and maintain the desired temperature of the fluid being transported.
Compared with austenitic stainless steel and duplex stainless steel, there are many comprehensive advantages of ferrite alloy steels for low temperature service, such as higher strength, better rigidity and lower expansion coefificient. There is not only better stability but aslo higher heat transfer efficiency. Tube & pipe for low-temperature service can be widely used in low temperature engineering. ASTM/ASME A/SA-333 Grades allow for cold temperature service to minus 150 degrees F. Material is always provided in the normalized condition at a minimum and Charpy Impact tested to a specific temperature range to assure compliance with the required service temperature.
Exceptional performance at temperatures down to -45°C with superior notch toughness and impact resistance.
Fine-grain structure with uniform carbide dispersion prevents brittle fracture in cryogenic conditions.
Economical alternative to exotic materials while providing reliable low-temperature performance.
Good weldability using conventional processes with minimal post-weld heat treatment requirements.
Precise control of chemical composition using electric arc furnaces with advanced ladle metallurgy techniques. Vacuum degassing reduces hydrogen content and eliminates inclusions.
Seamless pipes manufactured using hot piercing and rolling. Welded pipes produced using ERW or SAW processes with strict welding parameter controls.
Controlled heat treatment including normalizing at 815°C (1500°F), quench and temper, or stress relief to achieve optimal microstructure and properties.
Comprehensive testing including chemical analysis, mechanical testing, Charpy V-notch impact testing, hydrostatic testing, and non-destructive examination.
ASTM A333 Gr.6 Alloy Pipe is widely used in industries requiring excellent high-temperature, high-pressure, and corrosion-resistant performance.
Used in boilers, superheaters, and steam lines in thermal and nuclear power plants.
Ideal for hydrocarbon processing, ethylene cracking, and heat exchanger units.
Used in LNG pipelines, storage tanks, and vaporization equipment for cold media.
Ensures excellent thermal conductivity and corrosion resistance in cyclic operations.
Handles high-pressure oil and gas in extraction, refining, and transportation systems.
Resists acidic and corrosive environments in reactors, scrubbers, and distillation units.
