Large nozzle on pressure vessel
Large nozzle on pressure vessel
(OP)
Hello all,
Can someone please advise what calculation procedure to use for evaluating stresses at nozzle attachments larger than half the vessel diameter?
There is an existing heat exchanger that was designed to ASME VIII Div 1 in the fifties. It will experience uplift in a seismic event thus causing dynamic loads on the nozzles.
The shell is made of DN500, XS SMLS pipe (508mm OD, 12.7mm thk) and the product outlet nozzle is DN250, XS SMLS pipe (273mm OD, 12.7mm thk).
My understanding is that the given D/d ratio is outside the scope of PD5500 and WRC107. Can you please recommend an alternative procedure?
The nozzle loads (both static and dynamic) have been established from an AutoPIPE stress analysis.
Many thanks
Can someone please advise what calculation procedure to use for evaluating stresses at nozzle attachments larger than half the vessel diameter?
There is an existing heat exchanger that was designed to ASME VIII Div 1 in the fifties. It will experience uplift in a seismic event thus causing dynamic loads on the nozzles.
The shell is made of DN500, XS SMLS pipe (508mm OD, 12.7mm thk) and the product outlet nozzle is DN250, XS SMLS pipe (273mm OD, 12.7mm thk).
My understanding is that the given D/d ratio is outside the scope of PD5500 and WRC107. Can you please recommend an alternative procedure?
The nozzle loads (both static and dynamic) have been established from an AutoPIPE stress analysis.
Many thanks
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RE: Large nozzle on pressure vessel
This is based on a Transactions PVP Journal article by McBride & Jacobs in Feb 1980: "Design of Radial Nozzles in Cylindrical Shells for Internal Pressure."
RE: Large nozzle on pressure vessel
Many thanks for your input. However, Div 1 provides design by rules, not by analysis. Section 1-7(b)1 states that “the rules…do not include any analysis for stresses resulting from externally applied mechanical loads”.
Div 2, on the other hand, is design by analysis but the dimensional limits for nozzle attachments are d/D<0.5. The circle closes!
Section 1-7 that you refer to deals with bending and membrane stresses at nozzle/shell intersections due to internal pressure and is in essence an area replacement calc.
Regards