RogerT wrote:
Bob F wrote:
RogerT wrote:
I am running new plumbing lines in the basement of a 3-unit apartment
........
the connections would be. And, I believe there are copper to CPVC
adapters that either screw onto, or get soldered to (I am not sure
about that), the copper and then are glued to the CPVC pipe.
The last sentence describes what I'd use. Typically, a male copper
thread with glue on CPVC female fitting. It probably provides a much
better connection than a CPVC thread.

Thanks. I'm not sure if that would work. I read somewhere that there can
be problems with the female CPVC threaded fittings cracking when tightening
and that using male CPVC threaded lessens the chances of cracking.

I just went to Lowes and saw some "transition unions" that can be soldered
to the copper and then use a compression fitting (similar to a garden hose
connection/washer) that converts to a CPVC glue fitting. Here's a link with
some of those types of fittings:
http://milo.com/nibco-34-in-cpvc-tra...brass-and-cpvc .

And, any thoughts, suggestions, pointers etc. regarding the whole
CPVC (or CPVC and PVC) project would also be appreciated.
I would stick with the copper myself. If not, think about grounding
requirements.

The 3-unit building has all new electric wiring throughout. And 4 new
service panels (one for each unit and one "house" panel) were installed by a
licensed electrican with all the rquired permits, final inspection, etc.
The new service panels utilize the current code requirements including two
8-fot grounding rods located 6 feet apart; the required jumpers across the
hot water heaters, and the water meter, etc. So the electrical system does
not rely on any cold water pipe grounding. I think the new codes take into
account that people now use PEX, PVC, etc. which would make cold water pipe
grounding not reliable since there can be in the continuity of the pipes.


I'd go with the CPVC only on the half inch stuff. That's what I did
for most of my plumbing. The PVC is a little larger diameter so you
will get more volume for the same size if there might be a problem with
adequate flow in a cold water "main feed" system. Sounds like a rent
place? Large manifold pipe for supply, cutoffs to the individual units
etc. And when I had rentals I always kept the battery for the sawsall
charged, a metal cutting blade and various caps and plugs so I could cut
into a pipe and cap or plug it until a permanent fix could be done. For
transition from metal to plastic I usually screwed a threaded plastic
male into the female metal threads and then glued the plastic from
there. In your case a soldered female copper and then a male plastic.
That way if you need to you can cut the plastic line and unscrew it at
the transition. I never had it happen but supposedly the hot water can
back flow if a HWT over heats and flow enough hot water through PVC
under pressure to cause problems on the cold water side of a HWT.
Be sure to use only code approved CPVC glue for long, hopefully
forever trouble free joints and connections.