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Recent content by LS_SMS

  1. LS_SMS

    Can Service Pressure Exceed Design Pressure?

    My apologies, but I think you misunderstood my question. In fact, my question applies to both Sec. III and Sec. VIII. Regardless, thanks for sharing. I now realize that both sections have different criteria.
  2. LS_SMS

    Can Service Pressure Exceed Design Pressure?

    Hmm, fair enough. But I myself do not know either. Yes, I already looked but came up with nothing. And that's why I came here for some enlightening. I think that's the point of these forums. Otherwise, I could just cancel my user name and stop trying to learn from others here. Would you...
  3. LS_SMS

    Can Service Pressure Exceed Design Pressure?

    Thank you both! That makes sense for Sec. III. @TGS4, can you provide a Sec. VIII code citation where I can read it? My colleague prefers to see an actual statement from the code.
  4. LS_SMS

    Can Service Pressure Exceed Design Pressure?

    I'm using ASME, year 2023. In Sec. III and Sec. VIII vessel design, is there ever a situation where the service pressure of a defined load case may exceed the design pressure? For example, if design pressure is 100 psi, can I have a service load case that is defined at 150 psi? Please provide...
  5. LS_SMS

    Primary Membrane Stress Range for Thermal Stress Ratchet

    Thank you @TomLee777. But my question pertains to Pm in the ratchet calculation. And specifically, the question is, "is Pm a singular value (e.g., Pm from the design conditions in Part 5.2), or a range?"
  6. LS_SMS

    ASME Sec. VIII, Div. 2, Annex 3-F, Eqn. 8

    Yes agreed. What prompted my original post is that I blindly assumed the equation would output valid answers all the way down to 0 ksi. But if I understand correctly from your feedback, it seems that the equations are only applicable down to 13.6 ksi. Thanks for helping me see that.
  7. LS_SMS

    ASME Sec. VIII, Div. 2, Annex 3-F, Eqn. 8

    See the Mathcad image below for 2000 psi for 316 stainless at room temperature. Please also peek at my previously shared link HERE. The person graphed the natural log equation and it is going haywire as it goes below the fatigue limit. *edit* My screenshot does not show n_k, which was earlier...
  8. LS_SMS

    ASME Sec. VIII, Div. 2, Annex 3-F, Eqn. 8

    Is the Code Committee planning to fix the equations? Or was the added excerpt (quote below) supposed to act as the fix? It seemed insinuated HERE that they were actually fixing the equations themselves.
  9. LS_SMS

    ASME Sec. VIII, Div. 2, Annex 3-F, Eqn. 8

    Folks, I found another thread HERE about Sec. VIII, Div. 2, Annex 3-F, Eqn. 8. The equation has something wrong with it. That old thread was dated from 2018. In the 2023 version of the Code, the problem still exists. Does anyone have a status update on when they plan to fix this...
  10. LS_SMS

    Applied Acceleration At Boundary Condition

    Folks, I'm using Workbench v2023 to run a Static Structural FEA simulation. I have a simple model and want to apply an acceleration to the model. However, I want the acceleration applied to the boundary condition of the model, instead of the default, which is applying the acceleration to the...
  11. LS_SMS

    Primary Membrane Stress Range for Thermal Stress Ratchet

    Bump. A friend said, "Pm is definitely not treated as a range in this situation. Rather, it is the Pm from Part 5.2, Protection Against Plastic Collapse." And they went on to say that it may be confusing because Pm used to be a range prior to the 2007 edition. Does any of that ring a bell...
  12. LS_SMS

    Primary Membrane Stress Range for Thermal Stress Ratchet

    Folks, I am looking at 2023 ASME Sec. VIII, Div. 2, Part 5.5.6.3 for the Thermal Stress Ratchet check. This equation is provided... Pm is referred to as "primary membrane stress." Is it supposed to be a primary membrane stress range? Everything in the fatigue and ratchet assessment up to...
  13. LS_SMS

    Sec. VIII Div. 2, Part 5.4 Buckling

    Can you elaborate on this statement in Step 2 of the procedure? My understanding is that if the top head's eigenvalue is 2, the bottom head's eigenvalue is 2.5, and the cylinder's eigenvalue is 3, I need to run a single elastic stress analysis having all three components present, but each...
  14. LS_SMS

    Sec. VIII Div. 2, Part 5.4 Buckling

    Does that insinuate that each piece of the vessel should be run in the FEA separately (e.g., top head separate from the bottom head separate from the shell)? Or should the FEA analyze the entire vessel at the same time?
  15. LS_SMS

    Sec. VIII Div. 2, Part 5.4 Buckling

    Folks, I am looking at 2023 ASME Sec. VIII, Div. 2, Part 5.4.2 for the Method A Buckling Analysis. I plan to use the ANSYS eigenvalue buckling solver to perform the work. Here are some excerpts from the code... I see a common theme about "assessing individual components." If I have a...
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