What water supply flow rates should I maintain for my home

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Curious Skip

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Those issues aside, it make sense to just cut in a tee after the PRV and run a 1" PEX line over to the other apartment. That could just go to a new tee cut in somewhere in that apartment's distribution. That would leave you with a loop in the cold water line, which is fine and gives less pressure drop, but could be a bit confusing as far as shutoffs. So you'd want a ball valve at the supply end of the new run, and perhaps a ball valve in the current supply line to the apartment. The latter you could leave turned off if you want to avoid a loop.

Cheers, Wayne

That sounds like a plan right there. Thanks! However, my crimp tool won't do 1". Got to stick with 3/4.
But wait! That would mix filtered water with unfiltered. I can't use a loop, and I will have to have a second filter.
 
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John Gayewski

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Stop using that PEX. Look into how small those fittings are. They are going inside of a pipe that is already smaller than 3/4. Every one of those fittings kills your velocity and increases friction loss. If your going to use PEX you need type A expansion PEX and fittings. Also use 1" for the mains or manifolds.

Most times the difference in types of PEX doesn't effect much, but most times people aren't trying to squeeze the most from their water supply. When your at the border lines like your situation these things come into play.

I realize your probably not going to follow this advise. I'm doubting your going to rip out your pipe, but in the future realize that that type of piping doesn't do you any favors.
 

Curious Skip

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Stop using that PEX. Look into how small those fittings are. They are going inside of a pipe that is already smaller than 3/4. Every one of those fittings kills your velocity and increases friction loss. If your going to use PEX you need type A expansion PEX and fittings. Also use 1" for the mains or manifolds.

Most times the difference in types of PEX doesn't effect much, but most times people aren't trying to squeeze the most from their water supply. When your at the border lines like your situation these things come into play.

I realize your probably not going to follow this advise. I'm doubting your going to rip out your pipe, but in the future realize that that type of piping doesn't do you any favors.

Well, I know what you're saying. I can't rip out all the plumbing. And the reason I'm doing this is to alleviate the very problems you mention.

Also, I had the chance to do this all a better way when the house was going up, but I didn't know any better. I would have had a swell time arguing with my contractor! If I ever build another house things will be different....what is the saying...It takes building three houses before you start to figure it out? This was my first one.
 

wwhitney

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That sounds like a plan right there. Thanks! However, my crimp tool won't do 1". Got to stick with 3/4.
But wait! That would mix filtered water with unfiltered. I can't use a loop, and I will have to have a second filter.
On sticking with 3/4" instead of 1", you could get a similar result by sing two parallel runs of 3/4". But I would suggest that you'd be better off getting 1" PEX and a method to install it.

As to mixing filtered vs unfiltered, agreed that's to be avoided. So you come come off after the filter, or duplicate the filters, or duplicate the PRV and the filter, allowing you to run a higher pressure line over to the apartment.

Cheers, Wayne
 

Reach4

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You could get a clamp tool, and stainless steel clamp, instead of a crimp tool. But maybe you would want crimp to make things match. Can you borrow or rent a tool for your one-time use?
 

Curious Skip

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On sticking with 3/4" instead of 1", you could get a similar result by sing two parallel runs of 3/4". But I would suggest that you'd be better off getting 1" PEX and a method to install it.

As to mixing filtered vs unfiltered, agreed that's to be avoided. So you come come off after the filter, or duplicate the filters, or duplicate the PRV and the filter, allowing you to run a higher pressure line over to the apartment.

I could get my plumber to crimp the end fittings to a predetermined length of 1" PEX, then just connect both ends. The length of the run has about 10' of flexibility. I don't really want to install another PRV.

So....just a thought...could I use 1" PVC? Do pros use PVC for supply these days?
 

John Gayewski

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I could get my plumber to crimp the end fittings to a predetermined length of 1" PEX, then just connect both ends. The length of the run has about 10' of flexibility. I don't really want to install another PRV.

So....just a thought...could I use 1" PVC? Do pros use PVC for supply these days?
Not really. You can only use PVC on the cold. CPVC for the hot. If someone was going to go that route they would just use all CPVC
 

Curious Skip

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You could get a clamp tool, and stainless steel clamp, instead of a crimp tool. But maybe you would want crimp to make things match. Can you borrow or rent a tool for your one-time use?

I did look into renting, but the local place only has 3/4". I had my plumber install service to a new laundry setup in the apartment, and he used the clamps, so I have no issue with mixing the styles.
 

Curious Skip

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Note, not all PRVs are created equal...some will flow more volume than others. You'd get more volume to that apartment if you t'ed off before the PRV and used anther one for him.
I didn't give this enough thought when you first posted it. I've thought about lots of things that a real plumber wouldn't think twice about, and I've decided to (finally) get started on the project. I came back here to see about any further discussion, and when I re-read this about a second PRV, it hit me that that's exactly what I need to do. Our water dept. says there's about 150 - 200 psi at night.

And just to update, I did get a gauge for the hose bib, and learned that static pressure is 50. The tenant's shower drops it to about 42, and our shower open at the same time drops it to 35 psi.
 

Terry

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After the PRV valve, the cold should be 1-1/4" running a home with four bathrooms. Otherwise, you will get considerable pressure and volume drop when others are using plumbing fixtures.

screaming-in-shower.jpg
 
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Curious Skip

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This might be crazy, but the more I learn here about the does and don'ts, the less confidant I'm becoming. There's the code thing that I rarely understand the "why" part. Then there's the soldering technique...I read recently that you can easily use too much flux. The list goes on! I've been soldering copper pipes for decades, and once I learned how to clean a joint, I haven't had a leaker. But have a violated a code somewhere? Have I created a safety hazard?

Anyway, that leads me to this....I had a bout with Covid since I built up this assembly and I'm just now feeling like I could finish it. I look at it and wonder, Is it ok? I am using the existing PRV which will go between the copper and PEX on the right.

setup 2.jpg
 

Curious Skip

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So are you running 1-1/4" for the four bathroom home?
I was afraid you'd ask that. No, I only have a 3/4" incoming. It's not a 4 bath, but 3 1/2. The new line will serve 2 full baths, one of which is a guest room, usually empty.
 

Reach4

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I think you should use a 200 psi gauge on the input side.

3/4 inch PEX is much smaller inside than 3/4 SIDR poly pipe or 3/4 inch copper.
 

Curious Skip

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I think you should use a 200 psi gauge on the input side.

3/4 inch PEX is much smaller inside than 3/4 SIDR poly pipe or 3/4 inch copper.
That's what the boiler drain valve is for. I have a 200psi gage. I'll soon know what the incoming pressure is.

The reason I did not use bigger diameter pipe is simply that we have 3/4 PEX throughout the house now, and even with the poor layout, it provides "enough" water to get by. (Well, plenty for us, just not the apartment) And by adding the gauges, I can increase the pressure a little if I need to. The PEX run to the apartment is a 50' roll, with no fittings after it connects to the copper. I put another gauge on the downstream side of the new filter, which is at the far end of the run.
 

Jeff H Young

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Kind of hard to advise first determine whether anything needs done. could be a Tenant problem I think you need to see the flow turn water on in your shower let it run in a bucket for a minute . compare to his? then run your wash machine or whatever and check. yours and his then run his washer run his and yours. measure water and record each time Your the boss here you might want to do some major work you might not.
BTW Skip, Gotta say your work looks clean I like that !
 

Jadnashua

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One thing to keep in mind is that every pipe type has a maximum velocity recommendation. Copper is 5fps for hot and 8fps with cold. How much volume that equates to depends on the ID of the pipe. Pex is different and can support (somewhat) higher velocity without damage. Higher pressure can move the water faster through the pipes, but the faster it goes, the more friction you get that ends up limiting your maximum volume.

Too high of a velocity can, at least on copper, make some annoying noise, literally erode the interior of the pipe through turbulence, and create excessive pressure losses. The two things you'd notice first are the noise and the pressure drop...the erosion can take years.
 

Jeff H Young

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One thing to keep in mind is that every pipe type has a maximum velocity recommendation. Copper is 5fps for hot and 8fps with cold. How much volume that equates to depends on the ID of the pipe. Pex is different and can support (somewhat) higher velocity without damage. Higher pressure can move the water faster through the pipes, but the faster it goes, the more friction you get that ends up limiting your maximum volume.

Too high of a velocity can, at least on copper, make some annoying noise, literally erode the interior of the pipe through turbulence, and create excessive pressure losses. The two things you'd notice first are the noise and the pressure drop...the erosion can take years.
A few good reasons besides undesireable low flow not to undersize your piping.
 

Jeff H Young

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normal use I think being undersize wont harm but just dosent meet our minimum standard for a quality build to code. and we take guesses at what the end results are. Trust me we see a lot of this stuff it dosent all just fail.
 
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