I'm replacing the wallboard and tile in my 3/4 bath's shower. The 43 year-old plumbing is 1/2" copper pipe. The hot water supply comes straight up out of the concrete slab, into a Tee, over a foot into a
90 degree elbow and up about 4 feet along a stud into the bottom of the shower valve assembly. Very neat and straight. The problem is that to make it this straight, the original plumber had to run the copper pipe in front of the 2" steel vent pipe between the Tee and the wall stud. The vent pipe is almost flush with the wall studs. Because of this placement, the copper pipe sticks out about a quarter inch beyond the wall studs. I guess they either hollowed out part of the wall board to accomodate the pipe, or they didn't nail the wall board all the way against the studs. The old wallboard is too far gone to tell for sure.I want to replace the shower valve assembly and the hot water supply pipe to it because of its age and the fact that it's really green. I'd rather run the new copper pipe BEHIND that steel vent pipe so I can nail or screw the new wallboard (durock) flush against the wall studs. The only way I can see doing this is by adding 3 or 4 more 90 or 45 degree elbows to the copper pipe so it will go around the rear of the vent pipe and then up to the shower valve assembly. Or possibly bending a curve into the copper pipe, which I've never tried before.
I know the more connections in a copper line, the more the chance of a leak. But I'm fairly good at sweat soldering. What I want to know is if the extra elbows in the supply line will cause any restriction of the water, vibrations in the pipes or other problems when the shower is turned on.