Hi everybody!
Mr. Klein is right. Generally, when the pressure thrust force is employed, the strength criteria fail.
In my opinion, the most suitable approach for WRC 107/297 method is to employ "Include Pressure Stress Indices (Div 2)" option and TO IGNORE "Include Pressure Thrust" option.
The reason is that ASME section VII Div. 2 Pressure Vessel Code provides the Pressure Stress Indices values (at Article AD-560.7 and Table AD-560.7, or Article 4-6, Par. 4-612 - I have an older edition, I appologize if the reference paragraph numbers have been changed) in order to assess the highest peak pressure stresses at the "nozzle-shell" junction.
The highest peak pressure stresses are obtained by multiplying the nominal vessel hoop stress by those indices values. NO PRESSURE THRUST FORCE is employed.
So, since ASME VIII-Div.2 uses those pressure stress indices without any pressure thrust force, in my opinion this approach means that those indices include the pressure thrust force effect. This is quite natural since in the most of the practical situations, the nozzles are "closed" either by a blind flange or by a connected pipe with a direction changing (bend/elbow) and consequently the peak pressure stresses are computed by including the pressure thrust contribution.
Regards,
Dorin Popescu
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Dorin Daniel Popescu
Lead Piping Stress Engineer