The PRV valve protects every thing in your house from being damaged by too
much pressure. One thing is the rubber hoses going to your washer. Good
pressure is 60-70 PSI. I would put one in, especially since they are
recommending it.
"George E. Cawthon" wrote in message
...


Toller wrote:


Q1) Is this right?

Maybe. Most pressure reducing valves have have a bypass to allow the
pressure to equalize (if it is not clogged up). Check yours.

I keep my water tank at about 125 - 130. It has a pressure releaf
valve on
it. I'm of the opinion that most people feel the probablility of
needing
an
expansion tank is pretty remote. Give these conditions...

Q2) Would you think they are right?

I don't have an expansion tank because I turned my water heater way down
to
let it cool off, and then turned it up extra high and monitored the
change
in pressure. It never went high enough to matter, so I didn't bother
with a
tank.
The conventional wisdom is that you need one because a) your t&p valve
might
not work, and b) you don't want 120 pounds of pressure elsewhere in your
house. It is probably prudent to install one.

75psi isn't all that high but it is still better to use the valve and
possibly a tank. If your main valve actually shuts off, it is not that
much
work to put it in. (I also put in an additional main shutoff as long as
it
was opened up; the original one is probably pretty marginal.)

The more back up systems you add, the more chance of
failure. That's a good reason for not adding a pressure
reducing valve, especially when 80 psi is a normal working
pressure. Your t&P valve might not work, but how many tanks
blow up, how many times does the pressure get to 120 psi in
a house and do the pipes explode?