I analyze a non-standard flange in the piping designed to NC rules using Autopipe. Appendix XI is selected. Is NC-3658 automatically applied with Appendix XI ? or Do I have to manually input P+Peq and also manually calculate Mfs and Mfd ? In the flange analysis report I don't see Mfs and Mfd are listed.
Good day to you Geping,
Most questions on how the flange analysis calculations are performed can be answered by the following AutoPIPE help section:
Scroll down to the appropriate selection and open the folder to see step by step procedure with details on calculations performed.
Be sure to read all the information including all notes.
In your case, suggest that you review ASME Section III and ANSI Check procedures.
Regards,
Mike DattilioBentley Systems Design AnalystDesign Engineering Analysis group===================================================
I reviewed ANSI Check and Section III Appendix XI in Autopipe Help. I don't see the effective flange pressure (P+Peq) is mentioned in Appendix XI method. I did hand calculations for H and Wm1, and compared them to the H and Wm1 from flange analysis report. I found Autopipe Flange Check Appendix XI Method does not replace P with P+Peq; therefore my conclusion is Appendix XI Method in Autopipe does not check an NS flange for the requirements of NC-3658 (I do not find an option for checking either NC-3658.1, NC-3658.2 or NC-3658.3 in Autopipe Flange Check). Please advise whether my conclusion is correct.
Good day Geping,
Yes, you are correct that after reviewing the procedures used in AutoPIPE, that P+Peq is not considered as a default evaluation. If you wish to use this approach, please update the Flange analysis load tab Operating case = user. Then you are able to insert a defined Operating Pressure and temperature as needed.