Yes, WRC Bulletin 107 and WRC 297.

Of course, good engineering practice is to avoid transferring any loads onto a pressure vessel ...
- piping loads should be absorbed by piping supports;
- platform loads should be absorbed by structural steel; and so on...
in particular, the vessel should not be the 'sink' for the piping system's stresses...

Nozzle loads are usually checked by Finite Element Analysis (FEA) software, which takes you into a whole new realm of computation/complication.
PD55000 may also have something on nozzle stresses.