Water pressure in a house - 90 PSI too high?

[Ron Selzer]

Only been in this house 20+ years with water pressure higher than 90. Bought it new project build, nothing special
GUESS that mean every faucet and pipe in the house will blow up anyday, based on what people are saying here.
Do have an expansion tank on the hot water tank, doubled the size and hung it right when it leaked.
Have changed out water heaters, main shower faucet cartridge replaced, other two showers/tubs still original.
have installed numerous kitchen faucets due to SWMBO wanting new. never due to leaking
Have changed washer hookup hoses when washer got replaced.
Did change all plastic water pipe in basement to copper before drywalling the ceiling, still plastic in walls on main floor.

[John Goodin]

Sure Dan. Pressure reducing valves create a closed system where water can not flow back past the PRV toward the meter or main water supply. When the water is actively heated it expands creating more pressure in the system. The expansion tank installed on the cold water line of near the water heater looks similar to a small propane tank and contains an air bladder. As the hot water expands the expansion tank helps alleviate the increased pressure. The same goes for tankless water heaters.

As Ron said above he has had his house 20+ years with no issues and for many people that is probably the case. What I was referring to is simply the IRC and plumbing code which is typically written towards worst case scenarios. Expansion tanks cost about fifty bucks which is a relatively minor homeowner cost and are simple to install if you have a shut off valve on your cold water inlet a few feet before your water heater.

[Roger Feeley]

My house built 3 years ago is around 55 and I'm ok with it except for one thing. I have a traveling sprinkler and the outdoor spigot pressure is not sufficient to turn the wheels. That really cramps my watering style. I need closer to 80lbs just for the one outdoor spigot but I'm too cheap to pay a plumber to shut the whole house down, tee off the one spigot and install a second regulator.

[Dan Friedrichs]

Sure Dan. Pressure reducing valves create a closed system where water can not flow back past the PRV toward the meter or main water supply. When the water is actively heated it expands creating more pressure in the system. The expansion tank installed on the cold water line of near the water heater looks similar to a small propane tank and contains an air bladder. As the hot water expands the expansion tank helps alleviate the increased pressure. The same goes for tankless water heaters.

As Ron said above he has had his house 20+ years with no issues and for many people that is probably the case. What I was referring to is simply the IRC and plumbing code which is typically written towards worst case scenarios. Expansion tanks cost about fifty bucks which is a relatively minor homeowner cost and are simple to install if you have a shut off valve on your cold water inlet a few feet before your water heater.

Ah, makes sense! Thanks!

[Mike Cutler]

Sure Dan. Pressure reducing valves create a closed system where water can not flow back past the PRV toward the meter or main water supply. When the water is actively heated it expands creating more pressure in the system. The expansion tank installed on the cold water line of near the water heater looks similar to a small propane tank and contains an air bladder. As the hot water expands the expansion tank helps alleviate the increased pressure. The same goes for tankless water heaters.

As Ron said above he has had his house 20+ years with no issues and for many people that is probably the case. What I was referring to is simply the IRC and plumbing code which is typically written towards worst case scenarios. Expansion tanks cost about fifty bucks which is a relatively minor homeowner cost and are simple to install if you have a shut off valve on your cold water inlet a few feet before your water heater.

John
This is definitely different than on a well system.
There must have been some other changes to the codes, as the isolation valve for the cold water supply "used" to have be installed at the tank. Additionally, inlet and outlet check valves had to be installed at the water heater inlet and outlet. Water can only flow one way through my water heater, it cannot impulse back down the cold supply line. Maybe all new water heaters have this built in??
There is a "bladder" tank installed on well systems, but it's not for the same purpose. Mine is a 35 gallon tank that is precharged to the "cut in" pressure of the well pump, 32psi. The "cut out" for the well pump is set at 55psi. The "bladder tank", or "WellTrol" tank is there to reduce the duty cycles on the pump. A well pump is not a solid system.
Not sure I agree with calling a home plumbing supply system "closed". I understand what they mean, but the system is not closed. Every time a faucet opens pressure is changed. Semantics, I guess.
It's always different to see how things are done in different areas of the country.

To the OP

Stephen, no 60-70 psi is not too low for a water saver to work properly.

[Jerome Stanek]

My house built 3 years ago is around 55 and I'm ok with it except for one thing. I have a traveling sprinkler and the outdoor spigot pressure is not sufficient to turn the wheels. That really cramps my watering style. I need closer to 80lbs just for the one outdoor spigot but I'm too cheap to pay a plumber to shut the whole house down, tee off the one spigot and install a second regulator.

I would try an inline pump to increase the pressure

[Ken Combs]

Typical water pressure from my city is 90 psi. Few houses I have seen have water pressure regluators to lower it. How important is it to get it down to the oft recommended range of 60 to 70 psi? Given the restrictors built-in to modern faucets and shower heads, is 60 to 70 psi actually too low?

(I suppose that the city lines could have spikes in pressure.)

Usually the first things that show symptoms are toilet valves and water heater TP valve. Had that issue once and put a PRV in, but did it so that all my outside faucets got full pressure.

[Wade Lippman]

Sure Dan. Pressure reducing valves create a closed system where water can not flow back past the PRV toward the meter or main water supply. When the water is actively heated it expands creating more pressure in the system. The expansion tank installed on the cold water line of near the water heater looks similar to a small propane tank and contains an air bladder. As the hot water expands the expansion tank helps alleviate the increased pressure. The same goes for tankless water heaters.

The one I put in allows free backflow if the pressure is higher than the feed. It doesn't require an expansion tank.

[Justin DeSilva]

My water pressure shows 85-90 psi. I'm planning to install a 1/2" water pressure reducer on the 1/2" line after the 3/4" line with the water meter. When reading your post I began to wonder if I should instead install a 3/4" pressure reducer on the 3/4" line. The 1/2" reducer would be an easier install, running up the line. The 3/4" would require a return loop before running upwards. Any ideas what the preference would be?