Should L245 or Q235B be given priority for welded pipes?
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I would like to ask the experts here: I’ve seen several tables specifying the pipe grades for pipes made of welded tubes. These are generally used for diameters of DN 600 and above, which is understandable; for diameters below 600, seamless tubes are usually used. However, there are differences in opinions regarding the choice of material – some use L245 according to GB9711, GB 3091, or Q235B according to SY 5073. I’d like to hear everyone’s views. Thank you
The choice between L245 and Q235B for welded pipes depends mainly on the operating environment and requirements of the pipeline. L245 falls under the GB9711 standard and is primarily used for pipes transporting fluids such as oil and gas; it boasts good compressive strength and corrosion resistance. Q235B falls under the GB 3091 and SY 5073 standards; it is suitable for use with general low-pressure fluids such as water, gas, and oil, as well as in construction structures, and it has a relatively low strength. Considering safety and long-term performance, if the fluid to be transported has a high pressure or is corrosive, it is recommended to choose L245 first. For low-pressure transportation or structural applications in normal environments, Q235B is sufficient to meet the requirements, and it is relatively inexpensive. .
This post was last edited by lovepds on 2024-9-8 at 08:52. Q235B is a type of carbon structural steel pipe, typically used in utility pipelines; its design temperature does not exceed 350°C and its design pressure does not exceed 1.6 MPa. L245 has a wider range of applications. For specific usage restrictions, refer to GB/T20801.2