85 PSI Water Pressure

[SuperAcer99]

Last week, the screen at the end of the distributor tube in my water softener broke sending resin through the pipes in the house. A plumber came out and cleared the lines, replaced the bypass boot and flushed out the resin the water heater. The plumber suggested that the PRV be replaced because he thought that the 85psi static measured with his gauge was too high and that might have contributed to the water softener problem. He replaced the 1" PRV and the PSI on his gauge measured 70PSI after placement. I now notice that water doesn't come out of the shower head with as much gusto, which is annoying. I went to my city's website and they said that the minimum PSI should be 50 and the maximum 120. It indicated that most people should receive 80psi and that if your pressure is above 80psi, then you are required to have a PRV installed.

Was the original 85psi all that bad? How can I safely increase the water pressure? Should I install an expansion tank on my water heater to compensate for the increase in water pressure?

 

[LLigetfa]

I can't see your city water department caring about what the max pressure your softener is spec'd to. My softener manual says not to exceed 70 PSI.

Maybe you should try a different shower head.

 

[Sponsor]

 

[Jadnashua]

An expansion tank won't do anything about raising the pressure...it is designed to prevent the pressure from rising when you heat water in the tank. Without a path for expansion pressure to be relieved, the weakest thing will leak which is often the T&P safety valve on the WH. It could be the washing machine hoses swelling, or a toilet leaking, or somewhere else. Code generally requires an expansion tank when a prv is installed. There's a reason you should prevent the water from exceeding 80psi, things wear out faster and leak, sometimes catastrophically. You could raise the pressure to 80psi, but you probably wouldn't notice the slight increase - the prv is adjustable, not fixed.

 

[Jimbo]

40 to 80 is considered the range, with 80 really being on the high end. About 55 is probably the "norm" if there is such a thing. True enough you were used to much stronger showers than most folks have. Your guy's gauge might be reading high, because most PRV are factory set at 55, so if he didn't adjust it and says 70, then your 85 might have been 100 !!!

 

[Cacher_Chick]

I would recommend that you try some different shower heads. Most of the U.S. is quite happy with 40-60 psi, and it does not cause the problems that come with higher pressures.

 

[Gary Swart]

The expansion tank is needed with most PRV. Although some of the new ones have a bypass feature, most of them do not, and some of the newer water meters have. Read jadnashua's response on the role of expansion tanks. The air pressure in the expansion tank is adjusted to match the PRV setting. Likely the easiest thing to do is to have the tank charged to say 60 psi and when you install the PRV, use a pressure gauge to adjust its pressure to 60 psi. 80 psi will within the acceptable limits, is really too high.

 

[hj]

Your shower head could still be restricted with resin beads. 85 psi is not "bad", and most plumbing devices are designed to withstand 150 psi as a working pressure.

 

[Jimbo]

The expansion tank is needed with most PRV. Although some of the new ones have a bypass feature, most of them do not, and some of the newer water meters have.

It is not really anything to do with the regulator, or meter. All the bypass feature can do is prevent your house from rising above street pressure, but since in most cases that is higher than 80 psi, then we already have a problem. Thus the need for the XT

 

[Jadnashua]

There is often a misunderstanding on the bypass function of a PRV...as Jimbo stated, it only prevents the internal (home side) from getting higher than the supply. It is not magic, and cannot lower the house pressure to the PRV setting. Since the goal of a PRV is to prevent the house from getting to the supply pressure in the first place, its usefulness is somewhat limited. It does NOT take the place of an expansion tank, as its purpose is totally different. The whole goal of a PRV is to stabilize and prevent excessive home (internal) pressure. To do that, you need both the PRV and an expansion tank if your supply pressure is excessive. Also note, if you take the pressure reading during say the morning when everyone is taking showers across the town, the pressure reading may be much lower than if you were to take it at 3am when practically nobody is using water and they may be trying to refill the water towers and bump the pressure up.

If you want to know your peak water pressure, get a gauge that has a tattle tale (second hand) that shows the peak pressure reached and leave it attached for at least 24-hours. Then, you'll have a good idea of whether you need a PRV or not. With the PRV working properly along with the expansion tank, the peak pressure should not exceed the PRV adjusted value.