Hi Guys , I would like to understand a below query in PVElite Software .There is an option in Nozzle input dialaogue box says ID or OD Basis . If we consider the nozzle from Pipes then there is no much difference between both options.But For Integral / Hub & WN nozzles , Major difference in Area A6 . OD Basis - Area A6 is higher than ID Basis. I dont understand what is the difference between those and dono where to use it . Can anyone explain it please?