Water Pressure and PRV's

duece7 · Aug 1, 2016

Hi everyone,

We recently had a water softener installed and asked if we could have at least 2 of our 4 outside spigots bypassed so we would have normal water to water plants and flowers. Under our house which was built this year so everything is PEX and they tapped off the main water line before going up to our utility room where there is a pressure regulator that reduces the pressure for the rest of the house. He installed a small shut off valve inline on the new line going out to the hose bibs.

On a hunch I attached a PSI reader to the hose bib and the PSI reader only goes up to 200psi and it's maxed out at that. I called the water company to ask them why they didn't check that and they said they don't because it doesn't matter, the PEX are rated for 300psi and the bibs don't need to be regulated. This sounds like BS to me but figured I would check around before having a cow on the guy.

Thanks,
Mike

Mr_David · Aug 3, 2016

200 psi

That is still a lot. we have some areas that have 180 - 200 psi and it blows out he prvs to the units frequently. We would install a high range (75-125) prv at service supply, then a standard range ( 25-75 ) prv at the units.

common high pressure around here is about 150 ps1 reduced to about 50 - 60 psi

speedbump · Aug 3, 2016

Where is your new softener in relation to this PRV. Hopefully behind it!

frodo · Aug 3, 2016

you need a PRV for the WHOLE house...
why ?

during the day , the pressure is lower than it is at nite, because the system is being used.
at night the system is not being used and the psi can spike up passed the ratting of your tubing.

i would either reroute the 2 hose bibs so they are after the prv you currently have
or have a prv installed for those fixtures

plumb_bob_square_pants · Aug 3, 2016

Definitely agree with frodo. Take a guess how much water can come out of a 3/4" hose bibb @ 200psi in an hour. It's around a $10,000 insurance claim.
Frodo, your new avatar just got me. I thought I had a knat between my screen and the protector on my phone. I kept trying to squish it. I finally realized what it was before I took my phone apart.
Good one.