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.
The amount of pressure/flow loss feeding just the shower will
be negligible. 45's are better than 90's.
If you get a length of soft Type "L" copper tubing, you *can*
bend it to suit instead of using fittings.
Jim
Yes, each elbow will restrict the flow somewhat.
In a shower, however, the flow is most likely going to be more
restricted by the low flow shower head or shower valve. I doubt 3 or
4 more elbows will matter, unless you have very marginal flow and/or
pressure to start with.
Plumb it the way you want it, then test it before you close up the
wall, which is a good idea anyway in case you find a leak.
The extra elbows won't cause vibration problems as long as the piping
is clamped to the framing properly.
Oh, one more thing. Some of the new shower valves allow you to
reverse the hot and cold inlets (for so-called back to back
applications) by removing the cartridge, rotating it 180 degrees, and
reinstalling.
Sometimes that makes the piping simpler. When I reverse one, I write
hot and cold on the appropriate pipes with permanent marker to save
some headscratching for someone in the future.
HTH,
Paul Franklin
Nope, the copper pipe is running horizontally and it is right against
that vertical 2" diameter steel vent pipe. It won't push in even a
millimeter where the vent pipe is, and the vent pipe itself won't
move. Bending a curve into the copper pipe might be feasible, though.
Does this weaken the pipe and shorten its lifespan?