Not sure that will work in a horizontal pipe.Yes, PVC is waterer and will put an aquatic heating element inside to keep from freezing.
Vertical or Horizontal nipples?
Well, I have a thousand questions just put lots of pics of it in your coop age.
Go here:Great idea on coop page - where do I do this on the forum?
https://www.backyardchickens.com/articles/
Click 'add article' button in upper right hand corner.
Choose Member pages.
Might be more detailed info in the guides:
https://www.backyardchickens.com/forums/announcements-feedback-issues-guides.3/?prefix_id=3