We had sent you drg. no (Drg.No.5-07-02-01/03) giving 2 options for flange types i.e. WNRF and Lap joint.  This was for N13 & N14 nozzles of top assembly.  Please confirm your option.  Following are the briefs of the issue-
You wanted flange end connection to these nozzles pipes.  The pipes have threaded connection on the housing. The WNRF flange is welded to pipe. So while tightening the nozzles the bolt holes can go off-centre.  This issue is absent in Lap joint.          