Pressure Thrust in nozzle load calculation

[daniel1978]

Dear Friends

I am trying to calculate the nozzle loading.I saw other threads in this site about pressure thrust, but at the end i did not understand if i could consider effect of pressure thrust addition to effect of external load in nozzle load calculation . where in code i code get my answer? any other references?

 

[prex]

Pressure thrust is a loading acting on the nozzle through nozzle wall, so it should always be included in calculations of nozzle external loads.
What is often unclear is whether standard tables with minimum loads to be used in design do include or not the pressure thrust (presumably to be based on design pressure per piping class).

prex
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[TGS4]

You won't find the answer in the Codes - ASME Section VIII, Division 2, Article 4.5.15 is the closest that you will get, and it doesn't specifically address it.

Certainly, it is a real load that must be considered in the calculations. The issue s whether or not the pressure thrust loads are already considered in the development of the WRC537/297 calculations.

My opinion is that pressure thrust is implicitly handled in the development of the WRC537/297 approaches. To add the pressure thrust load again to the external loads is "double-dipping" in an excessively-conservative manner.

 

[XL83NL]

So a WRC107/297 nozzle load calc, where internal pressure is considered, does not include pressure thrust?

 

[TGS4]

The problem with the WRC107 (subsequently superseded by WRC537) is that there is no hole in the shell. Therefore, there is no "pressure thrust".

It has discussed in previous threads here and on LinkedIn about this point. There does not appear to be a consensus on the issue.

 

[XL83NL]

Thnx for the LinkedIn-link TGS4. Usually LinkedIn-threads are full of rather 'frightnening' questions (e.g. 'senior welding engineers' asking how FCAW works), however sometimes few threads are useful (like this one)

 

[TGS4]

Yup - there are a few topics (ASME PVP being one that we are aggressively moderating) with contributors that aren't even here on eng-tips. Dr. Brown's insightful comments on the BFJ topic ate very useful.

 

[chicopee]

Check out the attachment in PDF. If this is what your are looking fur, the document is mentioned on the top of the sheet. The appendix of this document shows you the calculations and don't forget the weight of piping that may be connected to the outlet of the SV if it is significant.

 

[XL83NL]

chicopee; not sure what that has to do with this thread?