The minimum requirements for attachment welds at opening are provided in ASME VIII-1, UW-16.
Fittings not exceeding DN80, as shown in Figure UW-16.2 may be attached to a vessel from the outside only.
See UW-16(f)(3).
yes r6155...In this case the fillet weld to the outside of shell is not possible due to jacket around the shell.(because the nozzle will attached after jacket setup. so we have to weld from inside of vessel shell only.)
can i provide fillet with the some inside projection?
can i use fig.uw-16 for inside projection? is it applicable?
You may be able to use the below interpretation to indicate intent, since it is internal to the jacket. The fillet is not required for reinforcing and the nozzle is stayed by the jacket. The external fillet on the jacket conforms to UW-16.1.
Probably also worth stating that UW-16.1 only provides some acceptable types of connections, it doesn't exclude other types of welded connections not explicitly listed. There is no detail provided for a shell connection through a jacket. Appendix 9, 9-6 would only refer back to U-2(g) IMO, whereby the above approach may be suitable.