In the past, I have buried some polyethylene water pipe with the copper tube
threaded in through it. The 1/2" size will hold 3/8" copper tube, or 3/4" if
you have a long run and want it easy to pull. The poly pipe comes in 100
foot lengths, is cheap and is reasonably flexible to curve out of the
concrete at each end and to go around any obstructions although you may have
to stake or strap it into place where you make a tighter curve than the
material naturally wants.

"johnnyzero" wrote in message
ups.com...
Hi,

I'm gonna be replacing the 60-yr-old 3/8" copper tubing that runs
through our concrete basement floor from the oil tank to the burner.
I'm gonna chisel out the old stuff, clean-up the channel, and then
re-bury the new tubing with concrete.

Anyway, from what I understand it's advisable to first encase it in
some type of outer plastic tubing or conduit to prevent corrosion
(that's why I'm replacing the stuff that's there). Any recommendations?

Thanks,
JohnB