David Todtman wrote:
....

Another question: the copper lines that will feed my new pex runs are half
inch. I notice that the so-called 'half inch' pex fittings (e.g., elbows)
are really not half-inch inner diameter but _much_ smaller. Wouldn't using
such a fitting simply mean I would not really have a half-inch line (but one
much smaller)? If this is correct reasoning then I reckon I should use 3/4
inch pex line.
....

There are at least two ASTM Standards for PEX, one for plumbing and
another for tubing and a zillion sizes of PEX as well as wall
thicknesses, etc.

I've never used the stuff but I'm sure there are sizes available that
will match ID/flow capacity of nominal Cu pretty closely, but whether
those are the most common in your local distributor's stock or the most
prevalent sizes used in general I don't know.

The one thing I do know is that the tool and fittings have to be
specifically made for the diameter(s) used and that the cutting and prep
of the ends is as critical as the crimp for a trouble- and leak-free joint.

While it's the coming rage, there's much to commend traditional Cu
except for price, unfortunately, imo...

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