I have a question for the "Z factor" in ASME VIII Div.1 (2023 version) Mandatory Appendix(MA) 1-2 Cylindrical Shells .
According to MA 1-2 (b) , equation (3).
Z = (P/SE + 1)
While, when I search on website , I found another formula for Z factor.
Z = ( SE + P) / (SE- P)
See link...