I'd like to retrofit our shower with a rain head by attaching a Kohler K-76331-CP diverter to where the current shower head comes out of the wall, then having one of the diverter's connections go to a regular shower head, and the other connection to the rain shower head. The diverter connection that I'd like to use for the rain shower has male threads labelled G1/2B.
Normally this connection would point downward and have a hand-held shower hose attached to it. What I'd like to do instead is have that connection point upward and attach a rigid 15-in pipe to it (e.g., a 15-inch nipple) to feed the rain head. I called Kohler, and they said that there's no problem pointing the connection upward. But I'm not sure how to join that G1/2B output to a rigid NPT pipe.
Is there a coupling I can use, or is there some other method of doing this–for example, a 15-in pipe that would have a G1/2B female connection on one end and an NPT male connection on the other end?