Offset surface and solid union

Dear all,
I’d be really grateful for some help as a deadline is approaching I’m at home with no one to ask for assistance!
I’m creating a series of pipes from a brep, which I’m trying to solid union. What I can’t understand is why I seem to have a different result between the two breps, which are the same shape (one is a slight offset). In one instance the solid union works in the other it doesn’t. I’ve change the tolerance, which hasn’t made any difference.
I’ve attached the file and would be really grateful for some thoughts :slight_smile:

Randall (1.7 MB)

If anyone else encounters problems, simpliyfing the original breps in grasshopper from the right click menu did the trick :slight_smile:

Hi there,
Thanks for getting back to me!
You were right and your explanation has helped me to get what was going on. I think the curves had kinks in them, which, as you said, was stopping the pipes from forming correctly.
Simplifying the BREPs and rebuilding the curves got there.
Cheers for the reply.