I have developed a problem in Routing / Piping that has to do with weld neck flanges, only: any size and/or weight class selected assigns a 4” Sch 40 pipe stub to go with it.  I have looked at the Design Table and it indicates, for example, that a 3” 150# WN flange should have a 3” pipe stub, etc. But dropping the 3” WN flange on the drawing produces a 3” flange with a 4” pipe stub.

Any suggestions?