Sorry for the reposts (is there a way I can edit a post?)
I discovered at work now that my tube and pipe styles do not work completely. Only the style with bends works. The style with knee's (or if i draw a 45 degree bend myself then the bend style also) give an error: Failed in engaging pipe with fitting. Connections do not fit because of different nominal sizes.
Stupid... I've tracked it down to an error when I make the piping style. (see the image)
What causes this one? The table and parameter mapping of the 45 degree and 90 degree bends are exactly the same but when I try to save it with the 45 degree I get the error. The 90 degree doesn't have an error on saving.