Toller wrote:
I have 3/4" copper hot and cold pipes running through the basement. 1/2"
copper pipes run off them to below sinks and then run up to the sinks.
The problem is one that is a 3' run from the 3/4" line to below the sink.
It is now attached to a 3/4" board attached to floor joists. I want to move
the 1/2" lines so they are even with the joists; that means moving them up
about 1.5". There is no problem with the sink as it is connected to the
1/2" pipe with a flexible connector. I am concerned about stressing the
1/2" pipe or the connection to the 3/4" pipe.

Seems to me that copper ought to have enough flex to accomodate moving 1.5"
over a length of 3', but I don't want to find out the hard way that I was
wrong. Anyone with experience here? The pipes are about 25 years old, if
the matters.

I want to put in a dust collector that requires 91", and I now have only
90"! Any place I can put it has problems with heating ducts or worse.

Just for reference, you're talking "tubing", not "pipe." Pipe, whether
steel, brass,
stainless, whatever, has much thicker wall, size spec based on ID, and
can
be threaded with std pipe thread on the outside. Tubing is made such
that the OD
is a close fit into std tubing fittings for reliable sweating of joint.

Copper can be annealed (soft) or un-annealed work-hardened. Note that
some
arrives as straight sections, some as coil. Guess which is annealed,
and which
is not.

J