What water supply flow rates should I maintain for my home

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Curious Skip

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I'm done, sort of. The intended result of good flow in the apartment shower was achieved. The tenant is very happy!

But there's a few leaks, all in the threaded connections. The 2 brass nipples between the tee and the PRV and the ball valve, and the copper adapter upstream from the ball valve all leak. Not much, a couple of drops per minute.

I don't know what to do now. I don't think I could get another full turn on the tee. I would also need to turn the ball valve a bit more, not sure if I can. I was afraid of this happening, because it seemed the threads on the nipples were too large. I couldn't get much engagement.

Should I get a pro in here? I am willing to attempt a fix myself, with a little more help from you guys. I just don't know.

Finished with leaks 2 resized.jpg
 

Reach4

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I think you are talking about the brass tee near the drain valve.

If you can't get another full turn, take it apart and add more tape. Even better is to use both tape and pipe dope. I expect good tape is better than cheap tape. Maybe consider Oatey pink tape.
 

Curious Skip

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I have found higher static pressure readings twice now. When I open a faucet, the pressure immediately drops back to the set point. This is on the new line to the apartment. I have two gauges, one just downstream from the PRV, and another downstream from the new filter. Both were reading 78 psi. PRV is set at 50.

What might this indicate?

78 psi 2.jpg
78 psi 1.jpg
 

Reach4

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Both were reading 78 psi. PRV is set at 50.

What might this indicate?
Normal thermal expansion. IMO seeing a pressure of 120 after a hot shower, and you then stop using hot would not be alarming, tho one person would disagree.

Having both gauges both read the same seems a bit surprising. If the PRVs are bypass type, then I would not expect there to be a big static difference. But I would expect you might have a 1 or 2 psi difference at times, because the spring-loaded bypass will have a little backpressure before it opens.

If your thermal expansion temperature never goes above 90, then you may have an extra-large thermal expansion tank, or you don't use a lot of hot water followed by not using any water. Flushing a toilet or having the ice maker fill would be instances of using water.
 
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wwhitney

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Just checking, does each water heater have a thermal expansion tank?

Thermal expansion will still cause a pressure rise with a thermal expansion tank, it will just be much less pressure rise than without one. Not sure if a rise from 50 psi to 78 psi is plausible, or if it indicates the expansion tank should be larger.

Cheers, Wayne
 

wwhitney

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Really? I am sure.
OK, sounds like you've looked at this more than I have. I said I wasn't sure as I haven't done any of the calculations.

Playing around with the Watts calculator you linked to, I don't understand why the calculated tank volume goes down as you raise the T&P relief pressure from 100 psi to 120 psi to 150 psi. From an uninformed basis, I would think you'd want to size the expansion tank so that the system pressure stays under 80 psi, regardless, and also so that the max system pressure maintains a reasonable differential from the T&P relief pressure.

If 20 psi isn't a sufficient differential, then I could see that with 100 psi T&P pressure, it designs for, say, 70 psi max system pressure, and with 120 psi T&P it goes up to 80 psi max system pressure. Which would explain a smaller tank size at 120 psi T&P vs 100 psi T&P. But then going to 150 psi T&P should still have a constraint of 80 psi max system pressure, meaning the tank volume doesn't change.

Cheers, Wayne
 

Reach4

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Usually the T&P pressure is set to 150, and I can infer that the Watts calculator then sets an implicit max of 130 psi for the expanded water. As a test, if I say that the incoming water is 129 psi, the calculator calculates a really really big tank required.

I suspect the implied max is the 150-20 to make sure the T&P never opens due to hitting the pressure due to WH thermal expansion.

If I had 75 psi from the city, and wanted to limit the maximum pressure to 80 psi, it would require a much bigger tank than is ever used.

If I am right, then the codes should change their wording. If I am wrong, then get ready for 50 gallon expansion tanks or people with 75psi water coming in adding PRVs. I would not like to see either of those. It would sure be a boon for tankless WHs and a problem for tank type users.
 
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Curious Skip

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Just checking, does each water heater have a thermal expansion tank?
Yes. I have three water heaters, each with an expansion tank. With the addition of the second PRV, each supply line now has a pressure gauge downstream from the respective PRVs. I have not noticed any increase in pressure on the original supply line, only on the new one.

The tank at the apartment WH is a model PFT-5. Well, I can't see the entire label...I can't tell the brand, but it seems to compare with the Watts PLT-5; 2.1 gallons would be a good guess for the size.

The WH is a 40 gal, temp is 130, T&P valve is 150 psi. I get a calculated total volume of .69. What does that mean?
 

Curious Skip

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Curious Skip

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The whole house filter I installed suggests a maximum pressure of 90 psi. Is there any possibility of causing a rupture with this thermal expansion?
 

Curious Skip

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Brand and model of that 3/4 prv. The 3/4 pex is smaller in diameter that the copper. Here a gpm chart


Like to see how the three wh are piped.

The PRV is a Zurn 70XL, bypass design.

And here are the three water heaters....

WH1.jpg
WH 2.jpg
WH 3.jpg
 

Reach4

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You might consider adding some support for the expansion tank on the AO Smith water heater.
 
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Taylorjm

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You might consider adding some support for the expansion tank on the AO Smith.
I would have thought that too, but in my research since I had to replace one on my boiler recently, is that this is how they are installed. Hanging without any support. At least on the ao smith one it looks like he has a decent pipe hanger on that copper line.
 

Curious Skip

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You might consider adding some support for the expansion tank on the AO Smith water heater.

I would agree. That's the original plumber's work. And it is 15 years old...probably going to have it replaced soon, and I'll make sure it's supported. Gonna get a pro to change it.

So are the expansion tanks sized as they should be?
 

Reach4

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Your pressure gauge readings would seem to imply they are sized fine.
'
You could hook up a peak-reading garden hose thread pressure gauge with a "lazy/tattletale" hand.

There are also calculators to calculate the minimum size tanks.
 

Curious Skip

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Your pressure gauge readings would seem to imply they are sized fine.
'
You could hook up a peak-reading garden hose thread pressure gauge with a "lazy/tattletale" hand.

There are also calculators to calculate the minimum size tanks.

Looks like I'm talking in circles...edited to recalculate.
 
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