Some values of NPS and schedule are inconsistent. for example NPS=30 and SCH=60.
Why PVElite doesn't notify me when there is such an inconsistency.

Hamid,

PVElite Version 5.0 August 2003 build will identify non-existent pipe size/schedule mismatches and return a message advising of this problem while on the nozzle dialog. Of course you can then choose a schedule that meets design requirements.