This may sound silly, but inquiring minds want to know!

I am installing a urinal in my pole barn. I have all the plumbing inside the bathroom interior walls except a short run to the urinal, which was behind the wall (well-insulated) so I don't have to heat the whole barn, just the bathroom (7 X 7).
I had the urinal pluming go through the wall for a foot, then back out to the stop valve. Of course, THAT'S the place the solder joint leaked!! (all copper). Instead of doing it like that, I'd like to go ahead and keep ALL the plumbing inside the interior walls, so I can easily get to the pipes anytime I need to. The problem is the stop valve would have to be "vertical" instead of horizontal, as is normally the case.

Flushometer is a Sloan Optima G2 automatic flush.

Question is, can I turn the stop valve 90 degrees, so that the inlet either faces up or down, instead of to the rear, which is normal? I can't think of any problems doing it that way, but would like the "pros" opinions.

Thanks in advance!!!