Maximum operating temperature of seamless pipes
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The material is 20# seamless steel pipe, in accordance with the standard GB8163. I’ve heard that the maximum operating temperature for this type of seamless pipe is 350°C, but I don’t know where to find this information. Could anyone please help me find it? I thank you all in advance: handshake:handshake.
Both GB150 and GB20801 have it
Should I look it up in Part 2 of the materials for 20801?
When considering the maximum operating temperature for seamless pipes, pressure must also be taken into account
For GB/T8163 seamless steel pipes, the maximum operating temperature can be up to 425 degrees, but the allowable stress is very low; this value can be found in GB/T20801 or GB50316, in the appendix containing tables of allowable stresses for materials.
At what low level of allowable stress can it no longer be used? I also looked into 20801. I asked many people, and their answers didn’t seem very convincing. I feel uneasy whenever I can’t figure this out.
In principle, temperatures above 425 degrees are not recommended for use; at room temperature, the allowable stress for 20# steel is 137, while at 425 degrees this value drops to 76. Moreover, a vertical line is drawn at 425 degrees on the standard, indicating that use above 425 degrees is not recommended. Reason: When carbon steel and carbon-manganese steel are used for extended periods at temperatures above 425 degrees, the carbides in the steel tend to graphitize. If you are involved in the design of pressure pipelines for the petrochemical industry, you should be aware that 20# GB8163 is generally used for low-temperature process media such as water, air, and nitrogen, as well as for process media under conditions of moderate pressure and temperature. For steam, GB5310 or GB3087 is generally used, while for process media, GB9948 or GB6479 and similar standards are typically applied.
This is specified as 20 steel in the \"Regulations on Technical Inspection for Boiler Safety\" TSG G0001-2012, regarding materials used for boilers; according to GB/T8163, its operating temperature should be less than or equal to 350 degrees! :):):):)