Flange length

[chris456s]

I'm new to Caesar II, so please bear with the silly questions.
I have just added a 300# flange to a 16" pipe.
The flange from Caesar is 149.225mm long.
However, ANSI 16.5 shows 144mm as the length of a weld neck flange (without the raised face).
Raised faces on 300# flanges are around 1.6mm (depending on supplier). I have checked several supplier catalogues and they show lengths (including raised faces) between 145.6 and 146.1
None of this matches the 149.225mm that Ceasar put in.. what is going on???

 

[RVAmeche]

I'm not sure why, it probably includes length for the raised face and gasket between the flange pair.

Either way it's 5 mm...