Regarding wafer butterfly valves and bolting: Can you have a mix of bolting types? I don't think so, but there may be a way to do it. In my example, a 20" CL 300 wafer butterfly valve has 20 x 1 1/4 - 8 (14 1/2" long) stud bolts w/ 2 heavy hex nuts and 8 x 1 1/4 - 8 (5 3/4" long) cap screws. Is there a way to get the bolts to report the proper quantities for both Isogen and BOM reports?

SaturnV

Conceptual only:
Make both studs and lugs... with Lugs as an optional part and make lugs fixed length. You may have to make them both fixed length, I cannot remember the piping rules impact on this.
I've made valves and bolts manufacturer specific in the past.

Ok. Are you saying you can have an optional bolts (like cap screws) tied to the standard bolts?

SaturnV

Add two bolt types to your spec and swap/add as req'd when modeling. Specific endotypes can automate this.