Questions about flanges
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It’s like this: the operating pressure of the medium is 4.2 MPa. So, is it wrong for me to choose a flange with DN25 and PN1.6? The key question is whether PN1.6 is suitable. Also, how should one choose a flange? Thank you O(∩_∩)O~
A pressure rating lower than the operating pressure definitely won’t work; PN6.4 is required. It’s a piping issue; check the pipe grade table from the piping or process engineering department – it should match the pressure rating of the pipes.
Since all the operating conditions are at 4.2, you need at least a value of 5.0; 5.0, 6.3, or 6.4 are all acceptable. When choosing flanges, make sure they are properly matched – the number of bolt holes, the diameter of the bolt holes, the spacing between bolt holes, the thickness of the flanges, and the diameter of the flanges must all be consistent. Avoid situations where, during installation, the thicknesses of the two flanges differ (i.e., the flanges do not meet the standard), or where the diameters or spacings of the bolt holes vary. Hehe. The commonly used standards are SH, HG, ANSI, and ASME; currently ANSI has been incorporated into ASME, while HG comes in European and American versions, with different flange sizes for each.
3# 275340019 Thank you; I discovered this today suddenly, as I hadn’t been paying attention to the operating pressure. I later changed it to PN6.3. Thank you
The poster must pay close attention to this: the operating pressure is 4.2 MPa, and the design pressure for the pipelines should be at least 6.3 MPa. However, the operating temperature also needs to be taken into account; if the temperature is high, then the relationship between temperature and pressure for flanged fittings must also be considered, as the allowable stress of materials decreases as temperature rises. When the operating temperature is high, a design pressure of 10 MPa may be necessary! Specifically, the design operating temperature and design operating pressure are used to consult the relevant specifications, in order to ultimately determine the design pressure
What was said on the 5th floor is absolutely correct. One more thing: the material issue also needs to be considered. Factors to consider when determining the pressure rating: 1. Design pressure (Note: not process pressure) ； 2. Design temperature (Note: not the medium temperature) ； 3. Material.
Colleagues upstairs, I’ve learned about it... But there’s one question: What does PN10/16bar mean? Can it be converted into pounds? :L
I learned something. The PN10/16 mentioned in that PN10/16 ISO refers to a nominal pressure of 1.0 MP/1.6 MP
Flanges with a pressure rating higher than 4.2 MPa should be selected; the choice of flange depends on the process piping.