Table of content
Introduction
Carbon steel pipes are used in many industries, among which the most common and temperature sensitive industries include oil and gas pipelines, construction, HVAC, and others. The temperature requirements for steel pipes vary among these industries, but regardless, their strength and durability remain unchanged.
How to understand the temperature effect of carbon steel pipes? This needs to be determined based on the production standards of steel pipes. The common production standards for carbon steel pipes include ASME B31.3 and ASTM A106/A333.
This article will mainly introduce the temperature limit, material composition, and the temperature tolerance of carbon steel pipes for different grades of application.
The typical temperature range for carbon steel pipes is -29 ° C to 427 ° C (-20 ° F to 800 ° F). This is just a regular temperature.
Low temperature carbon steel (LTCS) is a relatively unique raw material with a temperature range of -50 ° C (-58 ° F). There is also a heat-resistant steel grade (ASTM A335) that can withstand a maximum temperature of 650 ° C (1200 ° F). Except for these two grades, the conventional temperature of other steel grades is mostly within the typical temperature range.
What Affects the Temperature Range of Carbon Steel Pipes?
Within a typical temperature range, the specific temperature is also related to the following four aspects.
1. Carbon content
The amount of carbon content can affect its hardness and strength. The higher the carbon content, the stronger these two aspects, and of course, the relative ductility will also be lower. High carbon steel has higher strength and hardness at high temperatures, but is relatively brittle at low temperatures.
2. Alloy elements
The alloying elements in carbon steel, such as manganese, molybdenum, and chromium, can improve thermal stability and oxidation resistance. So alloy carbon steel can withstand higher temperatures than ordinary carbon steel.
3. Thickness and pressure rating
The thicker the steel pipe, the greater the pressure it can withstand. Of course, the thickness cannot be infinite, and it needs to be determined according to the ASME table during production.
4. Manufacturing standards
Different temperature requirements and material compositions correspond to different production standards:
Typical temperature application: ASTM A106/A53.
Low temperature application: ASTM A333/A334.
High temperature and high pressure applications: ASTM A335/A691.
Standard Temperature Range for Carbon Steel Pipes
The temperature range suitable for conventional standard carbon steel pipes, namely ASTM A106 Grade B, A53 Grade B, and AIP 5L steel pipes, is between -29 ° C and 427 ° C (-20 ° F to 800 ° F).
At high temperatures, carbides (graphitization) will decompose, resulting in a decrease in their tensile strength.
At low temperatures, it will become more brittle, and improper operation or design can cause fracture.
Typical Operating Conditions
| Pipe Grade | Type | Temperature Range | Common Application |
|---|---|---|---|
| ASTM A53 / A106 | Seamless / Welded | −29°C to 425°C | Steam lines, refinery piping |
| API 5L | Seamless / ERW | −20°C to 400°C | Oil and gas transmission |
| ASTM A179 | Seamless | −45°C to 400°C | Heat exchangers |
| ASTM A334 | LTCS | −50°C to 100°C | Cryogenic systems |
Low-Temperature Carbon Steel (LTCS)
Low temperature carbon steel is a type of carbon steel that is produced by lowering the temperature. This low-temperature carbon steel contains other elements that have been specially designed to maintain its strength and ductility at low temperatures. If ordinary carbon steel is exposed to low temperatures, it will lose its impact toughness and crack.
Common LTCS Grades
- ASTM A333 Grade 6: This type of carbon steel is commonly used for liquefied natural gas, refrigeration, and low-temperature pipelines.
- ASTM A334 grades 1 and 3: This type of steel pipe is mostly suitable for low pressure and low temperature environments.
Typical temperature range:
Typical temperature refers to the temperature that conventional carbon steel can withstand, ranging from -50 ° C to+100 ° C (-58 ° F to+212 ° F).
Those below this temperature mostly belong to low-temperature carbon steel.
High-Temperature Carbon Steel
High temperature carbon steel is commonly used in steam pipelines, boiler equipment, power plants, or pipelines that require transportation of high temperatures.
This carbon steel can withstand high temperatures because it has added other alloying elements (molybdenum and chromium), which can improve the performance of carbon steel at high temperatures.
Common High-Temperature Grades
ASTM A335 P1, P5, P11, P22: designed for up to 650 ° C (1200 ° F).
ASTM A691：used in high-pressure environments such as power generation
Key Considerations
Above 427 ° C (800 ° F), the performance of carbon steel decreases with increasing temperature, including hardness and strength.
Long term use in environments above 500 ° C (932 ° F) requires the selection of alloy carbon steel suitable for high temperatures.
How Temperature Affects Pipe Performance
The following are the conditions that occur for ordinary carbon steel at two extreme temperatures.
1. Under high temperature
- The strength and hardness of steel pipes will gradually decrease at high temperatures.
- Oxidation will occur on the surface.
- Long term high temperature can cause deformation.
2. At low temperatures
- The ductility of steel pipes will decrease at low temperatures.
- Low temperature can cause steel pipes to become brittle and break.
- It is not possible to add insulation layer on the surface of steel pipes at ultra-low temperatures.
3. Thermal expansion
Steel pipes can expand by 0.012mm/m ·° C when heated. Therefore, designers and users need to understand this phenomenon. Effective use to avoid cracking or expansion.
Temperature Range Chart by Carbon Steel Grade
| Standard | Temperature Range (°C) | Equivalent °F | Service Type |
|---|---|---|---|
| ASTM A106 Grade B | −29°C to 427°C | −20°F to 800°F | General purpose |
| ASTM A53 Grade B | −29°C to 400°C | −20°F to 752°F | Structural / Utility |
| ASTM A333 Grade 6 | −50°C to 100°C | −58°F to 212°F | Low temperature |
| ASTM A335 P11 | Up to 650°C | Up to 1200°F | High temperature |
| ASTM A691 | Up to 600°C | Up to 1112°F | High pressure / power plant |
Real-World Applications
1. Oil and gas industry
Conventional carbon steel can withstand the temperature generated during the transportation of oil and natural gas. But if transported in extremely low or high temperature environments, special alloy carbon steel pipes need to be selected.
2. Power generation
High temperature carbon steel A335 is suitable for this type of high temperature. In addition, it can also be used for steam boilers and superheaters.
3. HVAC system
Carbon steel substitutes (A106 or A53) can be used in this system.
4. Chemical plants and refineries
The pipeline system in such places requires repeated transportation of its products back and forth, thus it will be subjected to high and low temperatures repeatedly. Usually, coatings and insulation layers are added.
Maintenance and Selection Tips
- Choose the appropriate steel based on the working temperature and pressure capacity of the product.
- If there are requirements for corrosiveness, an anti-corrosion layer can be applied.
- If the ambient temperature is low or the transportation temperature is low, an insulation layer can be added.
- In high-temperature environments, regular non-destructive testing is required to ensure its performance is intact.
- The final production must meet the production standards.
Summary
Carbon steel pipes have a wide range of applications, but their temperature range should be considered when using them specifically.
- Standard carbon steel: -29 ° C to 427 ° C
- Low temperature carbon steel: down to -50 ° C
- High temperature alloy carbon steel: Up to 650 ° C
The selection of carbon steel is crucial, as choosing the right type of steel can increase the product’s lifespan and reduce maintenance costs. The introduction of this article ends here, hoping it will be helpful for you to understand carbon steel.
