Chasing down a PSI drop

[Ox45]

Hello All,

I just moved into a house and noticed some pretty bad water pressure issues. Static pressure is 40psi, which while low should be OK. If I open a single tap however, it drops to a little under 20psi which leads me to believe it's a flow issue. I had the water authority check the street pressure, which is at 50psi. He also took the meter off to make sure there were no blockages in that. Everything looked good. The house itself looks to have had all new pipes put in as everything is copper (1955 house). 3/4 main runs and 1/2 feeds, so nothing catches my eye in that department. What I would like to do next is make a device to test the PSI drop on the water authorities side to see if the issue is on their side, or in the house. I was thinking of removing the meter, and making a Tee that would attach onto the service pipe. On one side of the Tee would be a pressure gauge, the other a ball valve to open the circuit. Am I crazy in doing this or is there an easier way? Also, what size fitting would I need to attach to service line? It looks like 3/4, but the meter says 5/8.

Thanks!

 

[Reach4]

Before digging, I suggest checking the pressure at the hose bib outside nearest the incoming water pressure. That may split off before any filters or softener.

Try the pressure gauge at various places while you create the low pressure situation. Outside hose bibs, water heater drain, and maybe the laundry. Look for a whole house filter that may be getting clogged. Look for any other lumps or gadgets between the incoming water and where that incoming line tees off.

I think the 5/8 on the meter has to do with internal stuff and not what plumbing you hook up. There will be a special meter fitting that your plumbing hooks to. I don't have info on how to add your tee.

 

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[Ox45]

I've tried the gauge so far on both outdoor spigots, the hot water tank, and laundry slop sink. All show a huge PSI drop when another tap is opened up. No fancy things in the house like filters or softeners. Pretty straightforward plumbing.

 

[Jadnashua]

Do you have a pressure reduction valve? Probably not if your pressure is that low. Is the main shutoff valve a ball valve or a gate valve?

Do you know what the supply pipe from the road to your house is made of? That could be an issue. a 3/4" pipe isn't good for much more than about 10gpm and a 1/2" pipe about half of that (trying to get more ups the frictional losses and starts to limit the volume available).

Also, is there a significant elevation change between the street and your home? The static water pressure will vary with each foot of elevation change of 0.433psi/foot.

If it's not a restriction problem, there are booster pump arrangements you could look into. Well, even if it was, you could put one in, but may need a storage tank to act as a buffer.

 

[Ox45]

The street pressure is 50psi, and there is no PRV on my system. He said a 5-10 PSI drop from the street to the house is about normal.

Both shutoff valves on either side of the meter are gate valves. The incoming line is 3/4" copper, as is the tee off the main so I would assume the whole thing is. There isn't much of an elevation change, maybe 10 feet. This would help explain the 10PSI drop from main to house.

If I cannot find the source of the PSI drop, would a pressure tank help in this scenario? Like I said, I can live with 40PSI. But the drop to 19 is unlivable.

 

[Jadnashua]

A pressure tank should help (as used with a well), but an auxiliary pump could also be used with it to increase your overall home's pressure. But, a pressure tank would only provide better flow IF there's no downstream restriction and then, only until you drew it down so you had effectively just the 'normal' flow you have now.

To get a significant drop in working pressure implies one (or both) of two things:
- exceeding the capacity of the supply
- excessive frictional losses (by length, and that includes adding in friction for each elbow or change of direction).

It's possible that the gate on one of the valves is not functioning properly. Make sure that both of them are fully opened. If the handle just spins, it is the culprit.

 

[Dj2]

Things that are not clear:

- Are the gate valves at the meter fully open?
- Is the pipe from the meter to the house copper? (3/4" pipe is not enough, 1" is much better).
- How far is the house from the meter?
- Try shutting the main to the house at the meter. Is the meter showing water moving? If yes, you may have a leak in the pipe from the meter to the house.

 

[Ox45]

Things that are not clear:

- Are the gate valves at the meter fully open? They are as open as the turn will allow
- Is the pipe from the meter to the house copper? (3/4" pipe is not enough, 1" is much better). It is copper from curb stop to the meter
- How far is the house from the meter? The meter is in the basement
- Try shutting the main to the house at the meter. Is the meter showing water moving? If yes, you may have a leak in the pipe from the meter to the house. Water authority did a leak test and found nothing

 

[Ox45]

So while I was out of town, the water authority has done a leak test and replaced the curb stop. No changes. They are going to try changing the meter, even though it looks brand new.

 

[Reach4]

oth shutoff valves on either side of the meter are gate valves. The incoming line is 3/4" copper, as is the tee off the main so I would assume the whole thing is. There isn't much of an elevation change, maybe 10 feet. This would help explain the 10PSI drop from main to house.

Do either of those valves have a little drain fitting on the side? I don't know what the thread on those might be, but perhaps you could figure that out and make an adapter to a pressure gauge.

10 ft rise is 4.33 PSI.

 

[Ox45]

They don't, but I bought some pieces to tie directly into the line where the meter is connected. I will disconnect the meter myself, and tie it into the input line. I will have a pressure gauge and ball valve on this connector so I can see if I'm getting that 20+ PSI drop with an open valve. Hopefully this will narrow down which side of the meter it's on.

 

[Ox45]

So water authority came out today again to change the meter. They confirmed that the curb stop itself was not changed, just the sleeve going down to it. When the meter was off, we tested the pressure at the shut off valve on the main side and it read right at around 40PSI. He then opened the valve up into a bucket and said the flow was pretty dismal. Also the nipple that was between the valve and the meter had a good deal of mineral build up in it. So they replaced that, but no noticeable change. So it definitely appears that the flow issue is happening on the supply side. Bad thing is, in NYS I own all the piping after the curb stop. So I would be responsible for replacing that. Is there anything else I can test before I get the backhoe out and start ripping up concrete and dirt? Is it worth having them shut the water off to replace the old gate valve with a new ball valve since that nipple had build up?

 

[Reach4]

I suggest that you look through each of these threads:

https://terrylove.com/forums/index....zed-service-line-and-pull-through-poly.60769/

https://terrylove.com/forums/index....t-buried-main-water-line-from-the-curb.40434/

https://terrylove.com/forums/index.php?threads/water-line-coming-into-the-house-has-a-leak.66353/

 

[Ox45]

Another update:
They came and dug up the curb stop and did some pressure tests. The flow PSI out of the curb stop was 8PSI, so in other words clogged up. They replaced the line from the main and the curb stop, so now the flow issue is solved. But this now brings up another issue with the actual PSI. I (and they) have been testing the PSI during the afternoon when there isn't much draw on the system. But this morning my shower was dismal again (even though it was good last night) so I tested the pressure. It was reading at 29 PSI at the hose bib.
The digging got the attention of a few neighbors and I talked to them. They said the water authority did some work a few years back, and turned off one side of the line effectively making us the very end of a closed loop. And that ever since that all of their pressures have been dismal as well. So in the end I have a feeling I will be stuck with this PSI. So my question is, since I have flow again, can I put in an inline booster pump to get my PSI. And with this, should I do a tank or can I get just a pump?

 

[Reach4]

The digging got the attention of a few neighbors and I talked to them. They said the water authority did some work a few years back, and turned off one side of the line effectively making us the very end of a closed loop.

If you are not using water, the pressure gauge reflects what the city provides. So if the 28 PSI pressure only occurs while you are using water, there could be a further restriction in your lines. If you can get the neighbors to contact the water department as you have, you have a good chance to get them to increase the pressure.

Booster pumps exist, but it would be better if it did not come to that.

There are showerheads optimized for low pressure situations.

 

[Ox45]

The 28-30 was static pressure. It's up at 40-41 during off peak times. I just received a response back from the water authority pretty much saying "yeah that sucks, but there's nothing we can do about it". And they then suggested a pump/tank system as well.

 

[Reach4]

The 28-30 was static pressure. It's up at 40-41 during off peak times. I just received a response back from the water authority pretty much saying "yeah that sucks, but there's nothing we can do about it". And they then suggested a pump/tank system as well.

Maybe you could organize a group to visit a city council meeting to see if priorities could be adjusted.

 

[Ox45]

Knowing the county, it would take more than that to get anything large scale done.

If it does come down to it, would I need a large holding tank since I kind of have pressure? Would one of those combo pumps with a 6 gallon tank work?

 

[Cacher_Chick]

30 psi running pressure is really quite adequate if you are using decent fixtures/showerheads and the aerators are kept clean.

 

[Jadnashua]

If you have adequate flow, you do not need a big storage tank. The reason things like a well use a bigger tank is that on many, they just to not produce enough water to handle the needed flow. But, the smaller the tank, the more often the pump must run, so it's a tradeoff.

This Olde House installed a system a number of years ago, but you can still probably find that video on their website for some guidance. They bought an all-in-one pump/tank/checkvalve/control system and it only had a small tank on it. Enough so maybe you could wash your hands without having the pump come on, but any sustained use did require the pump. If you go with a larger tank, you could minimize the pump cycles, which helps with longevity.