If your 1 foot of isolated metal pipe serves an instant water heater I would want to be sure the EGC of the heater was effectively bonded to the pipe.
Different bonding requirements but I would say we are not required to bond that either.
1' of copper pipe does not constitute a metal piping 'system'.
This is much like the above argument about the steel building frame.
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250.104(A)(1) General. Metal water piping system(s) installed in or attached to a building or structure shall be bonded......
I can see no way we can call a isolated 1' piece of copper tubbing a 'system'.
By the way if you do apply the bonding to this isolated piece of pipe the conductor would need to be sized per table 250.66 not 250.122 so the EGC of the heater is not acceptable.
This IMO makes the thought of bonding small pieces of pipe even more ridiculous.
Bob
