WRC 297 for an 4" nozzle on the Vessel
WRC 297 for an 4" nozzle on the Vessel
(OP)
Dear All,
While i running vessel design calculation in PV Elite, For 4" Nozzle the calculation shows Dn/Tn is < 20 . Which is beyond the limitation of WRC 297.
My concerns are:-
1. Whether FEA analysis required for this 4 inch nozzle.??
2. Since the Dn/Tn is less than 20, So no need to perform FEA??
3. WRC 107 run for this same nozzle and it is passing with no warning and error, So is that enough conclude the nozzle are same for the external load etc.??
Your response are highly appreciated.
While i running vessel design calculation in PV Elite, For 4" Nozzle the calculation shows Dn/Tn is < 20 . Which is beyond the limitation of WRC 297.
My concerns are:-
1. Whether FEA analysis required for this 4 inch nozzle.??
2. Since the Dn/Tn is less than 20, So no need to perform FEA??
3. WRC 107 run for this same nozzle and it is passing with no warning and error, So is that enough conclude the nozzle are same for the external load etc.??
Your response are highly appreciated.





RE: WRC 297 for an 4" nozzle on the Vessel
My response to your concerns:
1. What does the client require (assuming you are a fabricator)?
2. No, the Dn/Tn ratio does not exempt your from performing FEA.
3. As noted above, the shell is okay, the nozzle may not be.
If you are not a fabricator, but the owner user, this is where some engineering judgement is required. What are the risks involved if the nozzle fails? How high are the nozzle loads? I assume PVElite extrapolates the WRC 297 curves to give you a result. You may be able to justify not performing FEA if the results from the extrapolated curves are relatively low.
RE: WRC 297 for an 4" nozzle on the Vessel