HI Nathan,

After i posted this, i had a look on our other software we use, ESTMEP. this diameter adjustment is easily done via the C1 & C2 connections under the Fittings section in the Database. What is very strange that i noticed between the two software, CADMEP  & ESTMEP,  that the options available to adjust differs from the two software packages. 

I will adjust all the diameters on CADMEP's effective diameter section and import that section of the database into the ESTMEP database,

Kind Regards