Placing families using vectors or orientations?

Good day everyone,

I have collected some information such as curve start and end points, whether they are equal or not, and the vector of the curves…(All this info is coming from Ducts that I have fed into Element.Location)
What I am trying to do is place families using these vectors for the orientation of the family, but I am stuck here and not really sure how to accomplish this.
Any help would be appreciated on this.