"Chris Lewis" wrote
According to Gary Slusser :

PEX is not harmed by freezing.

Their metal fittings may be.

Plastic plumbing (ie: all plastic irrigation systems) is a lot more
forgiving of freezing than copper or iron because it stretches somewhat.

But, expecting it to stand up to a lot of freeze-thaw cycles
is just asking for trouble. Which is why you drain irrigation systems
for example.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

In any type of plumbing, if the tubing expands as the water freezes, the
pressure is relieved, thereby the fittings don't break.

PE expands much more than other plastics, such as PVC, but PEX is able to
expand (its ID) more than any other type of water plumbing material without
failure. It has been tested to many thousands of expansions without failure.
Some is expanded to make its connections as opposed to crimped connections.
Heating it allows it to restore to its original shape, such as when a piece
has been kinked. This is from tech sheets and installation guides. Where do
you get your info from?

And as I said, the choice of the material for potable water lines should be
dictated but the water quality and since plastics are totally inert.... what
to use should be a no brainer... well for those that are aware of water
quality and metal tubing problem issues anyway.

Gary
Quality Water Associates
www.qualitywaterassociates.com
Gary Slusser's Bulletin Board www.qualitywaterassociates.com/phpBB2/