Water pressure - major pressure drop at my house when using water (credit)

[resonator]

Old, likely unrelated info:
Some 3 or 4 years ago SAWS replaced the bad water meter at my house in Stone Oak which had not been registering anything for months yet they continued to bill me hundreds of dollars above my previous years' averages. City councilman's staff was helpful in getting me a large (but still insufficient) credit from SAWS.
SAWS said "sorry, we over-read your meter" for five months.
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In early June I noticed that when watering the yard I had very little pressure at the indoor faucets and the sprinkler would work at about 20% usual coverage.

I have a pressure meter that I can attach to the nearest hose bib to the supply line from the meter.
Meter shows 80 psi with no water use, turn on a hose to a sprinkler (or the tub in the house), there's a two second surge of water, as it immediately drops to 15 psi and flow goes way down as expected.

This behavior happened all at once, and a few days later things were back to normal, but normal high pressure lasted less than a day, and the low pressure issue has persisted ever since.

Next door neighbors have no changes to their pressure.

I don't have a pressure regulator, several of my neighbors have added one. I have enjoyed the higher than normal pressures for the 9+ years I've lived in this house.

Bottom line, having been a pipeline engineer for 40 years, I know there is a constriction between my house and the street water main. Pressure is at line pressure until you ask for some flow and the restriction does what is expected in the way of a severe pressure drop.

I've exercised the shut-off valve upstream of the meter and given it some gentle hammer taps. No change.

I'm posting this to see if anyone has had this same issue.

Naturally I want to believe some piece of trash has found its way into the meter and is plugging up the works. Best case is it is a SAWS problem, and they fix it.

The meter's measurement function is OK, the little wheel spins and the numbers measure the water OK. Bills have been reasonable for several years now even though I no longer see any SAWS guy with his sensor taking the monthly reading.

I've heard several horror stories about dealing with SAWS and am looking for advice as how to get them to check the meter for an obstruction. Do I need a plumber's report to get their attention ?

Do you know a specific plumber who can handle this odd problem?

My fear is the meter is plugged/bad and SAWS says "hey, you have water, go away".

[less than usual]

[quote=resonator;65503637] I don't know but the problem does seem to be in the meter alright, I agree. An obstruction or a meter of poor manufacture.
Between your house and the water main out front are a couple of constrictions. The first of which is called a corporation fitted to the 8" Main ductile pipe running underneath the asphalt of your street. This fitting cuts down the insane pressure the main carries to a more maneagable pressure going into each residence. This kind of water pressure at the main is what puts fires out for the fire dept. Fire plugs have no pressure reductions and are attached directly to the main by equal size pipe, directly.
This is the biggest loss of pressure between your house and the main(probably an 8"main). At each each street address is attached a corporation, a stainless steel corporation- out from each corporation snakes a small copper pipe "2" for each house. The water main was perforated at each corporation and so by the end of the block when the entire main is exposed there are copper pipes coming off the water main at each corporation like snakes writhing up in the air all down the main from each street address. A strange sight indeed. All sorts of pressure testing goes on looking for sometimes troublesome leaks at this point.
From there each copper pipe gets routed, bent, from the main into the meter box in front of each street address. The pressure is regulated there again and has a meter installed to it. Constrictions I guess.
I have a good friend who just retired from saws, an electrical inspector, also a master electrician.
If I can get a hold of him he might just probably know the answer to your riddle. I will respond.
Any more questions on any kind of pipeline, gas, water, storm, sanitary. Just ask.There is my BOTTOM LINE. I have witnessed a lot of explosions in the gas pipeline industry. News choppers hovering overhead, that explosion at a Yamaha plant was bad. The wife called my cellphone to ask was I ok?
No matter how much care is taken it happens anyway.

Bottom line, having been a pipeline engineer for 40 years, I know there is a constriction between my house and the street water main. Pressure is at line pressure until you ask for some flow and the restriction does what is expected in the way of a severe pressure drop.

[SprinklerMan123]

Classic behavior for a failed Pressure Reducing Valve. Some homes in Stone Oak have the prv buried pretty deep and not in a box. Unless you've dug it up and verify it's not there, it's probably there.



If your meter is bad again, it will be obvious. Lack of dial movement, loud noises during flow.

[resonator]

First few years my pressure was always over 90psi. This year over 80 and plenty of flow. The restriction is just too big and too sudden for it to be anything other than a piece of junk in or blocking the valve or meter (or the pipe to the house of course).

Meter is not bad, as described above. It reads water used just fine. Could have a partial clog of course.

I will do some dirt digging, but doubt that a p.r. valve would be wide open, (not working obviously at 90psi) for years then suddenly drop to 20 percent.
Next door neighbor put in a p.r. valve last year. Did not have one before that.

[SprinklerMan123]

Minimum for the prv will be 25psi regulation. 115psi at the main is within expected range. I have seen prvs installed on houses with a failed prv and the plumbers did not know there was a failed prv because most plumbers do not know how to read a gauge.



What I'd do is dig up the water line after the meter to the sprinkler tee off. We know the problem is before the sprinkler tie in because the sprinklers are also affected.


Another possibility is an old gate valve that has rattled closed. I've seen that before.


Usually, water meter adapters are union type fittings. Easy to disassemble and flow test the meter. But good to have a replacement on hand in case it is corroded and collapses when you grab it.

[resonator]

Originally Posted by SprinklerMan123

Classic behavior for a failed Pressure Reducing Valve. Some homes in Stone Oak have the prv buried pretty deep and not in a box. Unless you've dug it up and verify it's not there, it's probably there.



If your meter is bad again, it will be obvious. Lack of dial movement, loud noises during flow.

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Thank you. Right you are ! SAWS man came by today and located the deep down PRV and showed me how it was singing. Strange how the darn thing went from allowing full pressure for 9+ years then failed in a more closed position.

I'll probably dig it up myself to save the plumbers a couple hours work. There's some shrubs that need to disappear too.

[SprinklerMan123]

You can put in a Zurn 70xldu-ss. Double union for ease of replacement, stainless steel spring for longevity with this hard water. Use Rectorseal tru blue thread sealer, sch 80 threaded nipples, and sch 40 couplings. Since it's deep, you can stack two boxes.


Another way to tell a failed prv is watch your gauge while the water is flowing. A restriction will show a steady needle. A failed prv will often show a vibration as the diaphragm moves.

[resonator]

Got the zurn -- happy water again at my house