On Mon, 20 Mar 2017 11:40:07 -0700, Oren wrote:

On Sat, 18 Mar 2017 09:09:18 -0700 (PDT), DerbyDad03
wrote:

Everybody immediately jumps up and tells you that you
have to have a pressure reducer. I have 120 psi water pressure
and have had hardly any problems. I have one hose bib that I
have a problem keeping washers in, but that hose bib is over
50 years old, and I suspect it just needs to be replaced.
So don't get in a swivet over people telling you what you
absolutely have to do.

As far as the leaks, you might try using the liquid pipe dope.
Put on a good thick coat and screw the threads up tight.

Bill

You will note that I mentioned fixtures in my response. I acknowledged
that the OP was have problems with his fittings, but I did not say that
the 120 PSI was the cause of the problems.

My point was that 120 PSI pressure can cause problems with many fixtures,
from toilet fill valves to washing machine solenoids.

If this site is correct, then the Uniform Plumbing Code requires PRV in
specific situations.

"The Uniform Plumbing Code and PRV

The Uniform Plumbing Code requires a PRV be installed if the water
pressure exceeds 80 PSI at the time the home is built, or for any
inspection of a plumbing task that involves a water test thereafter
resulting in high-pressure. "

http://ogradyplumbing.com/blog/under...ater-pressure/

If a PRV is required at 80 PSI for new builds and inspections, then
a PRV makes sense in *any* situation where the pressure exceeds 80 PSI.

One could argue that in older homes, a PRV is even more important because
fixtures and/or fittings may not meet the more stringent modern codes.

I agree. When I sold a rental property the home inspector said the
water pressure was to high ~ 85 PSI. He gigged me and stated I needed
a PRV installed. The house didn't have one. I opened all the faucets,
hose bibs, ran the water, dishwasher, etc. -- took pressure out of the
pipes and then took my own reading at a hose bib ~ 20 feet from the
street meter.. Argued the inspector had a faulty meter gauge. Buyer
accepted that so nothing was needed. The pressure had been tested
during the day when most folks were at work so pressure would be high.
Release that pressure and you get a different reading. At least in my
case it did. Would 120 PSI blow a PRV on a water heater? I don't
know.
Typical PRV on water heater is set to 150psi, so no, 120psi water
pressure will not cause the water heater valve to release.