85 PSI Water Pressure

12 years ago

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?

Comments (5)

User
12 years ago
If you had a PRV code requires a thermal expansion device like an expansion tank. Plumber should have checked for one when he replaced your PRV.

Might have resin from the softener plugging the shower head.
lazypup
12 years ago
That 50 to 120psi range is the standard for the municpal suppliers street mains.

For residential service the codes state that you must have a minimum static head pressure of 40psi and a maximum of 80psi.

In any instance where the static head pressure exceeds 80psi, either full time or intermittant spikes, you are required to install a PRV limiting the pressure to 80psi. The PRV must have an internal bypass for thermal expansion or you must install an expansion tank in the near proximity to the water heater.

Ref: IRC-2903.3.1 & UPC-808.2

Internal bypass type PRV's are extremely expensive and generally only used on large diameter systems exceeding 2". Generally all PRV's used for residential applications will require the expansion tank.

You must also keep in mind that since 80psi is the maximum allowable pressure all your fixtures are designed to work with a maximum pressure of 80psi. Any attempt to operate your system with pressures in excess of 80psi will instantly void all warranties and place you in serious risk of catastrophic failures.
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vgkg Z-7 Va
12 years ago
70 psi should give you a great shower, ours is 40/60psi (on a well pump) and even at 40 it's strong. Did the plumber clean out your shower head? might it be clogged?
kudzu9
12 years ago
Happs-
You should have great shower pressure at 70 PSI...as long as the shower head is not clogged. I just rebuilt my PRV because it was not functioning (I was getting 105 PSI in the house, and I couldn't adjust the PRV to lower it). After rebuilding it, I set it at just under 70 PSI. It didn't change the performance at any of the taps or my shower performance at all. I may not be able to shoot quite as far with my outdoor hoses, but that is about it.

I have a shower with two different showerheads, and one puts out a healthy stream and the other has always been less powerful. After redoing the PRV, I took the less-than-ideal showerhead off and looked at the strainer; it had a lot of fine crap in it. Cleaning that out improved things a bit, but I decided to try a new showerhead. The new one puts out quite a blast, which indicates to me that the old one had internal plugging of orifices I couldn't see or get at.

Other than cleaning out or replacing the shower head, the other thing to consider is how old your plumbing is. If this is an older home with galvanized pipe, you could have serious narrowing of the inside of the pipe to the point of having limited flow to the showerhead and elsewhere.
kudzu9
12 years ago
You don't want to try to increase your water pressure to above 80 PSI. Even 60 PSI should be plenty adequate if the rest of your plumbing is in good shape. It's definitely a good idea to install a thermal expansion tank, even if your pressure is below the 80 PSI threshold as this helps moderate increased pressure caused by the water heater. The PRV only reduces the pressure coming in...it can't keep the pressure down in the closed system that follows it: a water heater can drive the pressure back up if you don't have a thermal expansion tank, particularly if your water supply has a backflow preventer inline (usually right near the meter).

One other thing: Is the showerhead the only fixture not putting out adequate flow in the house?