145 pounds water pressure at bottom of hill

[virtualblues]

We live at the bottom of a huge hill. It’s uphill from here in any direction. The Certified Tester that did our Backflow Assembly Test Report last week says our supplied water is, “the highest water pressure in all the county that I've ever tested” at over 145 lbs. Learning of this high pressure coincides with an expensive recent plumbing repair, due to an underground pipe failure between the meter and our pressure reducing valve. Our irrigation system operates at full pressure as it branches off upstream of the pressure reducing valve. No irrigation issues. Home built 2007. The pressure reducing valve keeps the household pressure at 60 lbs. The pressure reducing valve is 18 feet away from the meter. The plumber that repaired the burst pipe (he didn’t know about the 145 lbs. of pressure at the time) now says the pressure reducing valve should be as close as possible to the meter with brass pipe & fittings. I contacted my water provider, Clark Public Utilities, they told me the high water pressure they provide is my problem. I want to ride out the recent repair’s 6-month warranty but be prepared with adequate knowledge for a long term fix should that become necessary. If installing a pressure regulator close to the meter is my solution, can I leave the existing pressure regulator as is? Any helpful advice appreciated.

 

[Reach4]

The pressure reducing valve is 18 feet away from the meter.

The pressure reducing valve (PRV) would usually be at the house or in the house. The advantage is that any pressure drop due to flow would be compensated for. So with the PRV at/near the house, the house pressure would be more consistent.

In the house, you would have a thermal expansion tank to take care of the water expansion caused by the hot water.

If the pressure into the PRV at the house is too high, you can have another PRV upstream.

The plumber that repaired the burst pipe (he didn’t know about the 145 lbs. of pressure at the time) now says the pressure reducing valve should be as close as possible to the meter with brass pipe & fittings.

Where was the burst pipe? What kind of pipe was it?

 

[Sponsor]

 

[virtualblues]

The PRV is within a yard of the house 18 feet from the meter. House pressure is consistent. Expansion tank on each water heater, yes. The pipe burst within a foot of the meter. All I know about the pipe that burst was that it was white with a brass colored coupler. It was the coupler that failed perhaps due to 145 lbs pressure.

 

[Jadnashua]

Water pressure is affected by gravity at the rate of 0.43#/foot. Usually, you own the pipe from the tap of the supply utility on into your home. If the stuff that's there can't handle the pressure, you may need to change it to a pipe that can handle that pressure better.

So, assuming there's a water tower at the top of that hill, the water level would have to be at least 325' above you. Keep in mind that as they fill that tower up, often at night, the pressure would rise because the water level would also rise. I'd want a pipe with at least a 50% excess pressure rating, and 100% would be better. You might want to get a pressure gauge with a peak reading (tattle tale) hand to see what your actual peak readings are. If the water in the tower got say an additional 50' of water in it, that's close to another 20psi that could be there overnight when the tower is being refilled.

Note that plastic pipe tends to expand/contract a moderate amount (both length and diameter, but it's much longer and more noticeable than the diameter) with temperature variations. If the pipe is not installed to account for that, that stress will eventually create fatigue and potentially cause things to fail. If the pipe is mostly underground, but part is exposed, UV on some plastic pipes can also affect the longevity of plastics. Being underground also helps moderate the temperature, but it still will vary. Metals can fatigue, too, but are definitely stronger. IF the pipe and/or fitting was rubbing against say a rock, over time, that could rub a hole in it. It's a good idea to bed the line in some sand or insulate it somehow to prevent that when backfilling. If you drive over the line, depending on how deep, that can cause problems as well. The deeper it is, the less likely that is to happen.

So, there's lots of reasons why things could have failed. Until you identify it, a repair may or may not last. I don't think the utility has any liability there unless they own the line, which is not the norm.

 

[Reach4]

The PRV is within a yard of the house 18 feet from the meter. House pressure is consistent. Expansion tank on each water heater, yes. The pipe burst within a foot of the meter. All I know about the pipe that burst was that it was white with a brass colored coupler. It was the coupler that failed perhaps due to 145 lbs pressure.

You think a brass coupler failed, and not a plastic pipe?

You might want to post a photo of the problem area.

I had presumed that the meter was up the hill. Maybe you have a separate meter for the irrigation.

 

[Cacher_Chick]

Any pipe and fittings that are in use for a water supply system should have no problem with even 200 psi. The pressure reducing valve protects things like the automatic fill valve on the toilets and solenoid valves on the washing machine. Household fixtures are best kept below 60 psi to ensure a full lifespan.