Need help with long run water line/tap/meter sizing

[wwhitney]

You need to measure flow rate and pressure simultaneously. Your baseline is static pressure with zero flow.

Cheers, Wayne

 

[saleenmav]

You need to measure flow rate and pressure simultaneously. Your baseline is static pressure with zero flow.

Cheers, Wayne

How would I do that? I took a pressure reading with nothing on and then with a couple different fixtures running. Thanks

 

[Sponsor]

 

[Reach4]

Ok, I think the first base pressure reading was a fluke, because I’ve tried it again several times and only gotten around 40psi.

That could be time of day related, as you get into the busier evening hours.

What I would like to see is the largest pressure drop, at close to the same time with the same flows, between the outside faucet and the water heater drain. It looks to me as if your big drop is not from the street to the house, and instead is within the house.

Are you sure you don't have a cartridge filter? Softener? Are you sure that the valve coming into the house is fully open?

Reading with no flow is important. That will correspond with the pressure at the street.

Then again take readings say with full cold on at the tub. When you run cold, and measure at the WH drain, you are measuring the pressure where the water tees off to the WH.

 

[wwhitney]

How would I do that? I took a pressure reading with nothing on and then with a couple different fixtures running. Thanks

When you turn on one fixture, put a bucket underneath the fixture with a 1 gallon mark on it, and time how long it takes to fill up 1 gallon. E.g. 20 seconds = 3 gpm.

Then you look at the pressure drop vs the flow rate, and if it's alot higher than the theoretical calculation for the piping upstream of your pressure measuring point, you have a kink or other blockage.

Cheers, Wayne

 

[Jeff H Young]

saleenmav, well your coming back with good important info! and 40 psi or 45 is not a bad reading its a fair amount. I dont quite see why a 1 1/2 meter on a 3/4 feed would be that much better than a 3/4 inch , however bigger is always better. 3/4 feed is lame though on rural property with 1/4 mile runs. im guessing your lots a little bigger than a city 50x100 postage stamp. I cant tell you what the acceptable readings should be. or exactly how many gpm should come out of a hosebib at the meter verses at the house 1000 foot away Id like to know but not sure how helpful the info would be to you. If it was my property I think Id want to know and then just for giggles Id put my same bib on at the fire hydrant (since I already have adapter and check that). Any way thats just what I would do , theres probebly better Ideas out there. if you can barely shower there are going to be interesting numbers

 

[Reach4]

saleenmav, well your coming back with good important info! and 40 psi or 45 is not a bad reading its a fair amount. I dont quite see why a 1 1/2 meter on a 3/4 feed would be that much better than a 3/4 inch , however bigger is always better. 3/4 feed is lame though on rural property with 1/4 mile runs.

saleenmav has 1.5” HDPE pipe from the meter to the house.

 

[saleenmav]

Here are some times to fill a gallon, along with the rating for the faucets. I can’t locate the rating for the dog bath. For reference to get an idea of drop from first to second floor, I included an identical bathroom faucet on the first floor powder room and a second floor bathroom. All of the ratings are at 60 psi. I’m of course not an expert, but I’m thinking I’m pretty much screwed if the pressure at the meter a 1000 feet away is only 45 psi. With the normal drop of roughly 5 psi over that distance, I’m only starting with 40 psi, which is already the bottom of the range, and then having to push that through a large footprint, two story house. Without more starting pressure, I think I’m pretty much SOL. Which is what I told the county was going to happen from the beginning.

 

[saleenmav]

Here is a link to the upstairs shower running and of the flow from the hose bib used. When I hook up a 90’ diameter sprinkler head, it sprays maybe 15’. If I add another sprinkler it maybe goes five feet.

 

[Reach4]

So how much pressure drop between the outside faucet and an inside pressure measuring point, such as the WH drain, with a given load? Run around and take two pressure readings while the same water flow, such as the cold on the tub, is running.

You can remote the location of a pressure gauge with a garden hose. I am interested in locating the pressure drop that I think occurs in your house. Your long haul pressure drop we understand. The drop within the house we don't understand.

There is a loss of pressure with altitude -- almost 1/2 psi ( 0.4335 psi) per foot of altitude. So that might be 4 psi drop from the first to the second floor. But I expect your WH is on the first floor.

If worst comes to worst, you can get a booster pump. However I still suspect a restriction in your house plumbing. I did not watch your videos.

 

[Jeff H Young]

I too havent watched videos yet ill go back and re read some of these I dont think a lav or shower gives a good reading on the main water system. I was thinking more like an open 3/4 pipe at where the main enters house if only a few gpms come through then there is obviously a problem if it just comes out like at 16 or 20 gpm then you got no problem on the main or meter. my numbers might not be spot on but this was my general idea. If water comes out a good rate at meter, you can leave the water department out of it.

 

[Reach4]

I was thinking more like an open 3/4 pipe at where the main enters house if only a few gpms come through then there is obviously a problem

I think the water pressure at the outside hose spigot at the house stays up at about 40 during the worst symptoms.

 

[wwhitney]

I think the water pressure at the outside hose spigot at the house stays up at about 40 during the worst symptoms.

Well, it's hard to tell from the presentation of the data (a pressure gauge with a max scale of 60 psi would give better resolution), but I gather the "dog bath" draws almost 4 gpm and causes a pressure drop of around 4 psi, while the "kitchen sink" draws about 1.2 gpm and causes an additional pressure drop of around 2 psi. Those pressure drops seem a bit higher than expected, but not enough to explain the complaints.

I know showerheads are rated based on the flow at 80 psi. Not sure about faucets, if that is also 80 psi. Perhaps it is normal for a kitchen faucet rated at 1.8 gpm at 80 psi to only provide 1.2 gpm at 40 psi?

A very interesting test that is somewhat more involved would be to insert a tee with pressure gauge between the faucet supply stop and the faucet supply line. Comparing the pressure drop during flow there to the pressure drop during flow at the hose bibb would indicate if there is any internal house piping issue.

Repeating the outdoor pressure drop vs flow measurements for a bath tub spout might also be informative. As would doing it with both the bathtub and the "dog bath" running (which will require a new set of flow measurements, as with both going, they should each flow less than with only a single fixture flowing).

Cheers, Wayne

 

[Reach4]

A very interesting test that is somewhat more involved would be to insert a tee with pressure gauge between the faucet supply stop and the faucet supply line. Comparing the pressure drop during flow there to the pressure drop during flow at the hose bibb would indicate if there is any internal house piping issue.

I think observations should include whether cold or hot or both was being drawn.

Monitoring the outside faucet pressure vs WH drain while drawing full cold at a tub would be interesting. That pressure drop should be low, since it only measures the drop from the tee to the spigot to the tee to the WH. Yet To measure flow from a tub faucet, I would time a 5 gallon bucket.

Wouldn't it be nice to know the pressure at the hose bib when 22 psi was measured at the WH? Yes, the flow too, but how much flow would it take to make a 15 psi drop not indicate an in-house problem?

Well, it's hard to tell from the presentation of the data (a pressure gauge with a max scale of 60 psi would give better resolution)

https://www.homedepot.com/p/Water-Source-Water-Test-Pressure-Gauge-WSPGH100/308724108 would be an improvement.

With a garden hose thread adapter, you could adapt to a 60 psi gauge. In fact, it almost looks like that Watts gauge in the photo could be separated from the adapter, and a standard 1/4 inch gauge screwed in instead.

 

[Tuttles Revenge]

When comparing the pressure drop at different points its important to understand that if you're not using the exact same equipment you will get varied results.

I had a customer who had this exact same issue in their triplex. But he and my plumber on site were taking samples from 2 very different hose spigots. One was a regular frost free hose bib and the other was the boiler drain at the water main. The pressure drop at the boiler drain was immense as it basically was a firehose of flow.. So I showed them the timed gallon trick. 3 sec to fill 5gal at the boiler drain and 45 sec at the hose bib. (totally paraphrasing .. not actual results)

In the OP's instance, the dog wash is the boiler drain. That outlet has almost no flow restriction (the reason we don't see a flow rate listed from the manufacture.) and the shower or whatnot with much less flow is similar to the FF bibb. Apples to Oranges.

The best test would be to use the same spigot at each location to determine the flow and pressure drop.

Ultimately my guess is that you, and all your neighbors have about 40-45psi and always will. You will learn to live with it or you will decide that a pressure booster is required to take a decent shower.

Also, I found a document from EPA that explains showerhead output. On pg 3 has a chart of pressure and flow ratings that showerheads are supposed to meet and indicates no difference in output from 80 to 40p
https://www.epa.gov/sites/productio...ws-products-support-statement-showerheads.pdf

 

[wwhitney]

Also, I found a document from EPA that explains showerhead output. On pg 3 has a chart of pressure and flow ratings that showerheads are supposed to meet and indicates no difference in output from 80 to 40p
https://www.epa.gov/sites/productio...ws-products-support-statement-showerheads.pdf

That chart is labeled "minimum allowable flow rate". For a 2.0 gpm showerhead, it's 1.5 gpm at both 80 psi and 40 psi. But any showerhead is going to have at least as much flow at 80 psi as it has at 40 psi.

The upshot, I think, is that the minimum flow rate at 40 psi is 1.5 gpm, and the maximum flow rate at 80 psi is 2.0 gpm. So the flow rate differential will be somewhere between 0 and 0.5 gpm.

I briefly tried looking for a typical showerhead flow versus pressure curve, without success.

Cheers, Wayne

 

[WorthFlorida]

Edit: looks like I can’t upload video. I’ll try to stick them on YouTube or something and add a link.

Videos can only be linked. Once the link is established the video will be nested.

 

[Jeff H Young]

saleenmav has 1.5” HDPE pipe from the meter to the house.

3/4 feed to the 1 1/2 meter then 1 1/2 rest of way to house. OP was complaining like it was not his fault so why not figure out if he is getting water at a decent rate at the meter to begin with. I guess we are all looking at it a little diferantly