New construction home with 85PSI,

[Nate848]

I have public water with a new house with a meter pit. Water line is about 300 feet long. I ran a 1" pex line from the main over to my pex manifold. I tested the psi in the house and it is at 85psi. Is this anything to worry about? I do like have good pressure when washing hands but some people to me 85psi is to high.

Would you reduce it or keep it at the 85psi and dont mess with anything. I dont have PRV anywhere so would need to buy and install it.

THanks in advance

 

[Jeff Handy]

Typical top limit is 75 psi I think.

Some fixtures or faucets might show early wear and tear from that pressure.

And faucets could splash, toilet fill valves could fail and maybe flood.

Experts will weigh in.

 

[breplum]

The UPC states 80 PSI for upper static pressure limit.

 

[FishScreener]

The American Water Works Assocition guidelines are to reduce to 80-psi at the bottom of pressure zones. The 75 from the main indicates you are very near the bottom of the segment.

It will work just fine.

 

[Jeff Handy]

Where was that 85 psi reading taken?

At an outside hose sillcock?

If it was taken on an upper level, then the first floor psi is probably higher.

 

[Mitchell-DIY-Guy]

Where was that 85 psi reading taken?

At an outside hose sillcock?

If it was taken on an upper level, then the first floor psi is probably higher.

In my new home the water main comes up into the laundry room where it splits into domestic service for the house, through a pressure reducing valve, and the service line for the outside sillcocks. The outside sillcocks do not go through the pressure reducer.

 

[Jeff Handy]

Mitchell that is why I asked about where he took the reading, and was it at a sillcock.

Pressure can vary all over the house.

And I agree that more hose pressure is more better, haha.

 

[FishScreener]

Mitchell that is why I asked about where he took the reading, and was it at a sillcock.

Pressure can vary all over the house.

And I agree that more hose pressure is more better, haha.

Roughly 1-psi for every 2.3-feet of elevation. Head is head. The engineers who design water lines and plumbing work in feet of head. Plumbers and the Firefighters use psi.

I keep trying to convince the fire guys at work that it would be lots easier to calculate the pressure at the engine for hose lay outs if they used feet of head instead of psi. But the guys who make teh decisions are so set in their ways that you can’t get them to consider it.

 

[Nate848]

Roughly 1-psi for every 2.3-feet of elevation. Head is head. The engineers who design water lines and plumbing work in feet of head. Plumbers and the Firefighters use psi.

I keep trying to convince the fire guys at work that it would be lots easier to calculate the pressure at the engine for hose lay outs if they used feet of head instead of psi. But the guys who make teh decisions are so set in their ways that you can’t get them to consider it.

I took it from the outside hose bib. I have a pex manifold and every line is separate.

 

[RS]

I would install a regulator, or PRV, and set it at 60 or slightly under. 55-60 is a nice pressure for a home, and it will reduce plumbing problems.

 

[rickwhoo]

I wish I had higher water pressure...

 

[Nate848]

I just got my PRV installed and now it really knocks and is a water hammer. Any ideas? It never did it before without a PRV. Thanks

 

[Jeff Handy]

Do you have a water heater expansion tank?

That might help cushion the shock from sudden closing of valves.

You can also add hammer arrestors on the shutoff valves at the washing machine.

 

[havasu]

I've also heard many have great success by shutting off all incoming water from the street, open up your faucets and flush your toilets, allowing them to drain down, creating small air pockets in your plumbing, then recharging the system.

 

[Nate848]

Do you have a water heater expansion tank?

That might help cushion the shock from sudden closing of valves.

You can also add hammer arrestors on the shutoff valves at the washing machine.

Right now I dont have the water heater installed, expansion tank or the washer dryer. The lines are capped. I have the sinks, shower and toilets installed.

 

[sawhillr]

A bit late to this discussion, but the water hammer is likely caused by the addition of the PRV. PRV's are also back flow preventers to keep potentially contaminated water flowing back into the city system and contaminating the whole system. Before you installed the PRV water pressure shocks could dissipate back through the waterline. This made the external line a shock absorber for your house system. The PRV prevents this. Once you install a water heater and an expansion tank, you will likely no longer have water hammer issues as it will absorb the shock. The water hammer is possibly more pronounced due to the high water pressure (assuming it is 85psi in the house zones and not just at the exterior hose bibs). If the PRV is reducing the pressure to 55 then this should also lessen the hammer effect.

 

[breplum]

Most good PRVs have bypass build in. That allows it to be an open system and not as sawhillr describes the issue with "closed" system.
Off the top of my head, Watts 25AUB, and Watts U5B both have bypass.
It should be easy to check yours.

 

[sawhillr]

Hi breplum,
Can you elaborate on the bypass you mention. It was my understanding that the PRV was required to not let water backflow (essentially a one way valve) and thus would not allow the city water line to act as a shock absorber. I am not a plumber, so very open to expanding my knowledge base.
Thx