How much pressure is too much?

justinae · Sep 20, 2010

We had a 1" line installed from the steet to the house. We then installed a MANABLOC manifold and hooked up a pressure guage to test leaks. It's reading 85 psi. The good news is that it has held steady for several days. But is that too much pressure for the manifold and to feed all the lines. Should I install a pressure regulator?

thanks much,
Justin

Gsalet · Sep 20, 2010

UPC says over 80 psi you must install a pressure reducing valve.. It's up to you if you want to roll the dice <grin>

Sponsor · 2022-01-29T12:20:58-0800

justinae · Sep 20, 2010

I think it sounds like a good idea. What is an ideal pressure? House has one 1 toilet, 3 sinks, 1 tub/shower, 3 hose bibs. It's less than 1000 sq. ft.

Gary Swart · Sep 21, 2010

The size of the house has nothing to do with ideal pressure. Excessive pressure will put a strain on toilet valves and clothes and dishwasher valves, and high pressure is not need anywhere in the home. 40 psi is about as low as you would want, 65 to 70 is more than plenty. I set my PRV and thermal expansion tank pressure at 50 psi, but I have two outside hose bibs that take off before the PRV so they have 90 psi with a 3/4" pipe, but that is way too much for inside.

NHmaster3015 · Sep 21, 2010

code is 80 lbs, but I doubt that 85 is worth putting a prv on, manifiolds and pex are rated much higher

hj · Sep 21, 2010

I usually set my PRVs between 75 and 85 psi, so in your case, I would do nothing.

Ian Gills · Sep 21, 2010

I wouldn't bother. That's in the high-end of normal where I live.

Jimbo · Sep 21, 2010

Problem is....how much does the street pressure vary....does it go up at night to say 100???

Jadnashua · Sep 21, 2010

If your pressure gauge doesn't have a 'tattle-tale' that shows the max reading, pick one up, then leave it attached overnight to see what happens. Often, at night, when most people aren't using water, the pressure goes up. The water company may also raise the pressure to refill water towers, so a one-time check of 85, may not represent reality.

justinae · Sep 21, 2010

really helpful stuff. so given that water pressure may spike, cost is probably less than $50, it sounds like a good "insurance" policy to me. I don't have a tattle tale pressure gauge, just a regular one.

thanks,
Justin

Jerome2877 · Sep 21, 2010

If your going to install the prv, I would also recommend an expantion tank on your water heater.

justinae · Sep 22, 2010

Jerome that's a good point. Thank you.

Runs with Bison · Sep 22, 2010

All good points. Went through the same thing with my home with regards to pressure. It had a PRV that was failing set at full output around 75-80 psig, but the home had no thermal expansion tank. When I hooked up a gauge that would show max pressure, I found it spiking to around 120 after water heater recovery from showers.. Since it had been like that for 14 years before I bought the house, I was ready to live with it. However, after putting in new toilets the pressure began spiking to 150 plus and popping the relief valve on the water heater--the old toilet fill valves had been acting as pressure relief around 120. So I went ahead and installed a small thermal expansion tank while having the PRV replaced. Runs nice and steady now.

How much pressure is too much?

Users who are viewing this thread

justinae

New Member

Gsalet

George the Plumber

Sponsor

Paid Advertisement

justinae

New Member

Gary Swart

In the Trades

NHmaster3015

Master Plumber

hj

Master Plumber

Ian Gills

Senior Robin Hood Guy

Jimbo

Plumber

Jadnashua

Retired Defense Industry Engineer xxx

justinae

New Member

Jerome2877

In the Trades

justinae

New Member

Runs with Bison

Member

Similar threads