I am having following query related to reinforcement calculation of nozzles.

Let due to internal pressure the thickness of shell required is 30 mm.and due to combined stresses the ration of allowable to actual is 0.95,If we are using 50mm as nominal thickenss of shell.
There is a nozzle in the shell.
then PV Elite considers 50x0.95=47.5 as required thickness for calculating area required and available in shell.

can any one tell me that whether ASME code address it in same way?

This is not in ASME code. They recently had an interpretation that nozzle area replacement calculation only applies to internal pressure (and external pressure).

But, as a matter of conservatism we included the effect of the longitudinal stresses in the nozzle reinforcement. Because, these longitudinal stresses will increase the stress at the nozzle opening as well.

ASME does not provide a procedure on how to consider this. But, UG-22 does indicate that you have to consider all possible loadings.

In our opinion this is a one conservative way of tackling this issue. If you do not agree with it then you can uncheck the corresponding box from Load Cases -> Consider External Loads for Nozzle Tr.

Mandeep,

Which interpretation you are talking about?

Also what case somnath is talking about? ie. combined stresses due to what...external piping loadings or ....wind/seismic loadings or...?

Mukesh Chopra
www.theculminates.com
M:+91-9428500192

Dear all
mr. Mandeep is absolutly correct. Kindly refer DIV - 1 addenda 2009 page 43 , defination of Tr .

Mukesh,

Here is the interpretation.

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Interpretation: VIII-1-01-119
Subject: Section VIII, Division 1 (1998 Edition, 2000 Addenda); UG-37(a)
Date Issued: April 22, 2002
File: BC02-2318

Question (1): A vessel has supplemental loads (as described in UG-22) applied to it such that the longitudinal stress governs the required thickness. Must this required thickness, based on longitudinal stress, be used as "tr" when conducting the nozzle reinforcement calculations in accordance with UG-37 of Section VIII Division 1?

Reply (I): No.

Question (2): If the Reply to Question (1) is “No”, then what rules apply?

Reply (2): See U-2(g).

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As pointed by Vishal the definition of the Tr in UG-37
correctly explains it.

Somnath is referring to the case when the longitudinal stress (due to wind/seismic or external loads) in the tower exceeds the circumferential hoop stress.