"Donna Ohl, Grady Volunteer Coordinator" wrote in
message ...
On Sun, 17 Feb 2008 06:19:34 -0500, Nate Nagel wrote:
the nipples on the top of your new heater should already be dielectric,
so adding a dielectric at the end of your water pipes would only protect
the copper flex.

Hi Nate,
That dialectric stuff confuses me to no end.

Dielectric unions are needed to prevent reactions between dissimilar metals,
causing leaks years from now. This is why copper hanger brackets or straps
should be used with copper pipe.

Sometimes though, unions are used simply to facilitate future disassembly;
no desoldering required, just a big wrench.