On 5 May 2005 08:06:12 -0700, someone wrote:


Raise it far enough and the TPR valve opens. It doesn't
matter if the backflow preventer is 1ft or 1 mile away, the pressure
will still rise.

Harry K

Theory over practice.

If the check valve was a distance approaching inifinity away, being
that the total volume of expansion is finite (and rather small), and
there being some (very small) elasticity in the pipes, tank, valves,
water itself, you COULD be far enough away that the now small rise in
pressure (from a very small volume being added to a very large one)
would not be enough to force the valve open.

Has practice shown that 150 feet is enough?

Try it and see. If his T&P keeps dribbling, he could still put the
tank in. But he may find he doesn't need to.


Reply to NG only - this e.mail address goes to a kill file.