NRAM,

You have a valid concern. My (personal) recommendation is that you always consider the flexibility of the terminal point (nozzle) assuming you can properly compute that/those value(s). As you noted, this will lower the loads at that specific restraint, and can influence the surrounding (associated) piping.

As to your specific situation - where did you obtain the displacements you want to enter? Was this was a manual computation (according to API-650)? If so, I suggest you specify those displacements on a CNODE connected with the API-650 flexibilities to the piping (nozzle) node. This is why on the API-650 nozzle dialog you have the field (edit box) to enter a CNODE.