Steve Barker wrote:

As far as I know, there is NO such thing as a left hand pipe thread or
fitting. It was a troll posting that. Not to mention, EVEN if there were
such a thing, both ends would surely not tighten up at the same time.



L/R couplings are in use today and trace origins to the very
earliest days.

http://www.plumbingsupply.com/leftright.html