Typically you would use the "Batch Assign Long Description Styles" function of Spec Editor to configure a new format or string for the properties you would need.

I attempted to configure the long description as you mentioned above. However, I wasn't able to use the size field for the second part of the string.

I am assuming you would want something similar to this for a reducer that changes in size and schedule (as an example):
4" SCH 80 LE x 6" SCH STD SE
Would be something like:
<Nominal Diameter>" SCH <Schedule> LE x <Nominal Diameter>" SCH <Schedule> SE
So there are two property fields for size and schedule in the spec, but the long description style editor only recognized the first entry for size and schedule.
The workaround I tried was to create 4 new fields:
SIZE1
SIZE2
SCH1
SCH2
But unfortunately you cannot use custom property fields in the long descriptions.
I have submitted this issue to the development team.
Thank you,
Jason Drew
Designated Support Specialist