Good Morning to everyone,
I'm a engineer that works in an company that build Pressure Vessels for Oil Refinery, Petrochemical & Thermal application. I ask you the following question:

In the nozzle reinforcement calculation (using the ASME VIII Div.2 Part 4 Cap. 4.5) in Hydrostatic test condition which allowable stress is necessary to use? (assuming same material for nozzle and vessel)



If necessary, for define the allowable, use the equations 4.1.4 and 4.1.5 (ASME VIII Div.2 Part 4 Cap. 4.1.6.2) is correct to consider Pm = σcirc and Pm + Pb = PL?
Thank you and regards

σ circ is the general primary membrane stress. However, PL is not Pm + Pb, but the local primary membrane stress. To check which stresses act at specific locations (in any case what the Code says) look into "Table 5.6 - Examples Of Stress Classification" and "5.6 Supplemental Requirements for Stress Classification in Nozzle Necks".

Mr. Frohnert, Thanks for your answer.
I kindly request to you another help.
The equation 4.5.43 (ASME VIII Div2 Par.4 Chapter 4.5) define the value of Sall to use in the nozzles check (Sall = 1.5.E.S); is correct use this equation also in the hydrostatic test condition, replacing S with 0.95Sy (so the equation becomes 1.5.E.0.95.Sy)?
Thanks for your help.

That´s right.

Thank you.