In high-pressure hydrogen pipelines, when the system is made airtight, nitrogen cannot reach the maximum operating pressure of hydrogen. How can airtightness be ensured to guarantee safety?
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In high-pressure hydrogen pipelines, when the system is made airtight, nitrogen cannot reach the maximum operating pressure of hydrogen. How can airtightness be ensured to guarantee safety? Hydrogen is 6 MPa, but nitrogen can only reach 2 MPa? How to achieve airtightness? Is it nitrogen + a little helium? Or nitrogen with water for pressurization? Or nitrogen + hydrogen?
In this case, the safest and most effective method is to use “nitrogen + a little helium” for the airtightness test. Helium is an excellent leak detection gas; it can escape through extremely small leak points. Using a helium mass spectrometer leak detector, the location of leaks can be detected with great sensitivity. Nitrogen is used as the primary filling gas to achieve a high pressure (although it does not reach the operating pressure, it is sufficient for preliminary pressure testing), with a small amount of helium added for more precise testing. Both the “nitrogen plus water for pressurization” and “nitrogen + hydrogen” methods have their drawbacks. The former involves a change in the medium, while the latter poses safety risks, as the mixture of gases may lead to an explosion hazard in certain situations. Therefore, when it is not possible to achieve the operating pressure fully, using a \"nitrogen + a little helium\" approach is a relatively safe and effective method for detecting gas tightness. .
This post was last edited by Weilongwu on 2024-9-12 at 08:11. Please ask the design institute to change it to a sensitivity leak test; this test involves lower pressure levels. Otherwise, it won’t pass the acceptance criteria. For specific details, refer to Section 9.3 Leakage Test of the \"SH 3501-2021 Code for Construction and Acceptance of Steel Piping Systems for Toxic and Flammable Media in Petrochemical Industries\"
Just press the nitrogen compressor to operate it
No, do you mean to rent one temporarily?
There are also temporary ones; if the system isn’t large, it’s fine to buy a smaller one； If that doesn’t work, just use a hydrogen compressor; however, it will cause damage to the compressor.
There are gas boosters that cost a few thousand dollars each; you can just buy one. They’re also driven by instrument air