What are the requirements for the wall thickness of benzene pipelines? Can a flat-weld flange with a neck be used?
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I’m using 20# steel with grade 8163, and the pressure rating is 2.5 MPa
Benzene pipelines must use necked butt weld flanges; necked flat weld flanges cannot be used
Do you know where there are standard or normative references? The owner must follow it, it’s painful:dizzy:
The standard boiling point of benzene in a medium is 80 degrees Celsius. Benzene, being an extremely hazardous medium, falls under GC1.1 class of pipelines (some consider it a highly hazardous medium; when the design temperature is above its boiling point, it also belongs to GC1.1). According to TSG D0001-2009, pipelines made in accordance with GB/T8163 cannot be used directly as GC1 class pipelines. It is specified that such pipelines must undergo ultrasonic testing, and only those that meet the standards of GB/T8163 at least at L2.5 class can be utilized. Although there is no explicit prohibition against using flat-face flanges on GC1-grade pipelines (or perhaps I simply haven’t found the relevant standards), for flanges used on GC1-grade pipelines it is necessary to ensure their sealing performance; therefore, WN flanges are recommended. I’d like to discuss this with everyone; if there are any mistakes in the above views, please point them out and explain why. Thank you. Additionally, as for benzene medium pipelines, or other GC1-grade pipelines that can be made of carbon steel, how should the selection criteria for carbon steel be determined? Can GB8163+ ultrasonic testing, GB 9948, and GB6479 all be used as appropriate for GC1-grade pipes? What types of equipment or media are relevant when using these standards? Additionally, what are the price differences between these pipes? I would appreciate some guidance from those who are familiar with this topic. Thank you
Article 7.4.1, Clause 4 of SH3059-2001 stipulates that for process materials and pipelines carrying flammable media, plate butt welding shall not be used.
No, we use forceful butt-weld flanges here!
Pipes of GB5310 20g grade should be used; the cost of ultrasonic testing for GB8163 pipes is not lower than that for 20g grade pipes
Have there been any comparisons of the data for the 20G material specified in standard GB5310 with the 20 steel specified in GB6479 and the 20 steel specified in GB9948? Thank you
According to 20801 4.1.1, pipelines for transporting benzene must have a temperature above its boiling point to be classified as GC1 grade pipelines. Below 80°C, it can only be classified as GC2. So, as long as the temperature does not exceed 80°C, the 8163 can be used; however, WN flanges should still be employed.