I am modelling a pipe which connects to the vessel but I do not know the allowable loads of the nozzle, so I am following the WRC modules.

To design as the highest safety factor, I shall use ANCHOR for the nozzle's node.

Can I use the flexible nozzle to the model instead of an anchor ? Will it cover the design not to fail on the vessel's nozzle ?

Thanks.

Using an anchor at the nozzle node is the most conservative method, since the nozzle will pick up more load. If you do this, and you don't have a problem with the system or the nozzle, then you should be good.

If you do have issues with the system or the nozzle, then you do want to introduce the nozzle flexibilities (because it is more accurate, but not as conservative).

Thanks a lot Richard.

I have more questions as below:

1. If I am medelling a vertical vessel with nozzle coming out at the bottom. How can I specify the type of the vessel, Cylinder or Spherical ?

2) In case that it neither Cylinder or Spherical. Let's say it's a Flat Plate. How can we specify the vessel's type.

3) And what should I input for the distance of the stiffener and the distance of the opposite stiffener ?

The WRC297 bulletin provides stiffness computation methods for "cylinder-cylinder" intersections only. This bulletin does not provide methods for nozzles on heads or flat plates. Attempting this means you have stepped out of the scope of WRC297. (Note PD5500 does address nozzles on heads.)

There are other posts on this same subject, with suggested approximations, that can be accessed using the [Search] button above the calendar.