On 25-Oct-17 7:55 AM, trader_4 wrote:
....

Agree, that would indicate that the water is somehow leaving the pipe
on the apt side of the shutoff valve. If the leak was in the supply
line entering the house, before the valve, when you turn it back on
after awhile there should not be the sound of water rushing in to fill
the pipes. It sounds like whatever is leaking or taking the water
not only takes whatever is leaking past the shutoff valve, but also
some of the water that's already in the pipes. Which would suggest to
me that whatever it is, it's more likely on the lower levels. If you
had something leaking at the highest faucets I don't see that partially
draining the pipes when the shutoff valve is off.

Siphon effects?

I'm curious what we're talking about in absolute flow rate when isolated
both the low/high rates. That could possibly lead to some klews as to
what would be that volumetric capacity.

And, has the "true isolation" test been run; granted if they're all ball
valves they have far better chance of actually holding than the more
typical gate valve...

What's the size(s) of the various lines out of curiosity?

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