High-pressure hydrogen pipeline
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I would like to ask everyone: The medium flowing through the pipeline is hydrogen at room temperature, and the operating pressure is 20 MPa. What should be the appropriate design pressure? Under such high pressure, is 1.5 times the operating pressure (30 MPa) a safe design pressure? If 30 MPa is chosen as the design pressure for calculation, then the pressure class of the corresponding high-pressure pipeline will be 32 MPa. With such a high pressure rating, and 304 stainless steel being used as the material for these pipes, are there any available tables specifying the wall thickness corresponding to different pipe diameters? Do I still need to calculate the wall thickness myself?
Experts, please show up! Stop diving~~
As shown in the figure: I found a very old standard, H31-67, which is a standard for high-pressure pipes and fittings in the fertilizer industry. However, this standard is too outdated, and the outer diameter of the pipes corresponding to their nominal diameters differs from that specified in current standards. Furthermore, this standard does not specify what material the pipe with this wall thickness is made of. So it seems unreliable; it can only be used as a reference, not as a basis for design. I’m not sure if experts have any experience in this area; please give me some advice!
This post was last edited by yjaigtt on 2018-9-27 08:41. Regarding design pressure, it is recommended to refer to Section 4 of GB/T20801.3, GB50316, GB150, or other standards. A 1.5 times working pressure has no basis. It is recommended that you recalculate the wall thickness of high-pressure pipes; choosing an appropriate wall thickness can help save on costs.
I have reviewed these standards, and none of them specify the relationship between the design pressure and the operating pressure. However, GB150 states that when the maximum allowable operating pressure is indicated, it is possible to use that value as the design pressure for the container. I chose 1.5 times because I had never encountered such high pressure before, and I did it as a precaution. The recalculation of wall thickness you mentioned – according to the calculation standards in GB50316 – requires knowing the design pressure; otherwise, it’s impossible to carry out the calculation ； I’m currently struggling with deciding what appropriate design pressure to choose at a working pressure of 20 MPa.
Pressure pipelines must have calculation sheets, but these sheets do not need to be archived
I know how to calculate the pipe wall thickness, but how is the design pressure for pipes determined? I can’t find the standards for calculating design pressure; please advise!
It’s hard to say; they choose a nominal pressure of PN160 for hydrogen at 5 MPa, so it’s not excessive to go with a pressure rating of 32 MPa for 20 MPa
I have worked on a high-pressure hydrogen pipeline with a pressure of 12.2 MPa; the design pressure chosen was 13.5 MPa