Pressure thrust in PV elite

[FPPE]

Hi,

I would like to better understand how is pressure thrust incorporated in PV elite calculation, when the following option is activated:

"Select to include the pressure thrust force (P*A) in the nozzle radial load. Pressure thrust is added to Internal Pressure and Occasional Pressure (Pvar).
This value is only available when WRC 107/537 is selected for Analysis Type on the WRC 107 tab."

It says "Pressure x Area", but how is it added to internal pressure and occasional pressure? Since Pressure x Area is expressed in [N] and Pressure is in [N/mm2].

Thanks in advance

 

[Snickster]

Pressure thrust is a radial force at the nozzle due to pressure force PxA being tranfered to the vessel wall through the nozzle circumference, just like any piping load is. This force produces local stresses, membrane and bending stresses, that add to the general sustained membrane stresses due to internal pressure, just like other piping loads do. Allowable stresses for local stresses at nozzles in combination with general sustained and occasional membrane stresses are given in the ASME Code. Attached is a COADE bulletin on how to handle pressure thrust loads.

Also see this preveous engr tips discussion:

https://www.eng-tips.com/viewthread.cfm?qid=518557

 

[GD2]

OP,
You are correct. The PVElite statement is ambiguous.
Infact, all external nozzle load should be included when doing a WRC 107/537 analysis.
External loads include thermal, sustained (pressure and weight) and Occasional (wind/seismic). It is the ‘axial’ or ‘radial’ (per WRC definition) component that is required to be considered.

GDD
Canada

 

[FPPE]

Thank you GD2!