Is it advisable and possible to run for this PEX layout, without using elbows (i.e. just bends)?

[Mini Me]

In the picture below I need to transition from copper to PEX (top right side of the picture) and the feed the vanity the shower column and the smart toilet.
At a first sight, besides the two transition couplings, I would say I just need three Tees that the rest of them (1,2,3,4) could be bends with adequate support. The copper is 1/2 so I will transition to the same unless I am being told to use larger. Main supply is above, in the ceiling, that is where the to copper verticals at the top right side are coming from

 

[IPDQKWID]

I ran 11 PEX lines (hot and cold) with almost no elbows (fewer crimps, fewer whatever rhymes with crimps that means goddammit), aside from the toilets, which I used something like these: https://www.menards.com/main/plumbi...1-c-19654.htm?tid=-6191148689469333078&ipos=2
There are all kinds of supports, I've used three different types, and in a few days will pressurize the water supply in the addition. I've got 99.9% confidence that the bends will perform as well as crimped-on elbows. Anywhere I have a crimp, I'm installing an access panel.
By no means am I a plumber, but that's exactly what I did.
If I can get to it, I'll post a picture here of the rack I built to support 8-9 bends in a limited space.

 

[Sponsor]

 

[Mini Me]

If you are not a plumber I dont think you would have a device to generate presure. How do you plan to do that?

 

[Jadnashua]

Depending on the diameter and the type of PEX, each one will have a minimum bend radius, but it's actually fairly small. TO make neater right-angle bends, they sell bend supports. You need to ensure your holes in the studs are big enough so that you can pull the pipe through without scoring it or damaging it. They make plastic supports to help hold the pipe in those holes, keeping it centered.

So, yes, you could make the runs without fittings to change direction. Keep in mind that the ID of PEX is smaller than the equivalently sized copper. It's generally recommended to limit outlets on 1/2" PEX to one fixture...and, if you have a high flow situation, you may want to upsize to 3/4" for the PEX part, and reduce to 1/2" for any branches. FWIW, making the connections to the valves sometimes is easier if you use copper, as then, you have something rigid you can clamp or anchor to a support. Some valves have holes that will allow you to anchor it, but some rely on the supply pipes being able to be anchored.

 

[Reach4]

If you are not a plumber I dont think you would have a device to generate presure. How do you plan to do that?

If city water, the city provides pressure. If it is well water, the well pump usually provides pressure.

 

[Mini Me]

I thought the idea is to subject the work to pressure higher than it will ever experience via the current source

 

[Reach4]

I thought the idea is to subject the work to pressure higher than it will ever experience via the current source

If done, that kind of test is required, it is usually done with air.

See page "90" (actual 98) of
https://www.firstsupply.com/UserFiles/Documents/inRiver/Original/4834_Uponor_Q4771010_Manual.pdf

 

[Gsmith22]

Depending on the diameter and the type of PEX, each one will have a minimum bend radius, but it's actually fairly small. TO make neater right-angle bends, they sell bend supports. You need to ensure your holes in the studs are big enough so that you can pull the pipe through without scoring it or damaging it. They make plastic supports to help hold the pipe in those holes, keeping it centered.

So, yes, you could make the runs without fittings to change direction. Keep in mind that the ID of PEX is smaller than the equivalently sized copper. It's generally recommended to limit outlets on 1/2" PEX to one fixture...and, if you have a high flow situation, you may want to upsize to 3/4" for the PEX part, and reduce to 1/2" for any branches. FWIW, making the connections to the valves sometimes is easier if you use copper, as then, you have something rigid you can clamp or anchor to a support. Some valves have holes that will allow you to anchor it, but some rely on the supply pipes being able to be anchored.

In addition to using the bend supports as Jadnashua suggests, I would just add that bending 1/2 PEX is easy and 3/4 PEX a little bit more difficult but not impossible. Forget bending 1" PEX (even with bend supports). Popeye couldn't bend 1" PEX into its supposed minimum bend radius with the supports and I would highly recommend using tees and elbows for 1" PEX. 1.25" PEX and above is not intended to be bent (at least based on literature I have read) and tees and elbows are required.

 

[Mini Me]

I have 1/2" copper and I am transitioning to PEX
I already have this kit
https://www.amazon.ca/iCrimp-Cinch-Tool-Removing-function/dp/B07CCH5JWG
As far as I can see it works with any size between 3/8" and 1"
Which PEX size should I use ? I am feeding a shower a vanity and a toilet

 

[Reach4]

Which PEX size should I use ? I am feeding a shower a vanity and a toilet

1/2 for hot to shower +vanity. 3/4 for cold to toilet+vanity+shower.

If vanity hot alone, 3/8 would be better, but 1/2 is cheaper. So few use 3/8 PEX.

 

[Mini Me]

1/2 for hot to shower +vanity. 3/4 for cold to toilet+vanity+shower.

If vanity hot alone, 3/8 would be better, but 1/2 is cheaper. So few use 3/8 pex.

That is interesting ..why different sizes for cold and hot? Any other reasons besides the fact that one line has three fixtures while the other has just two?

 

[Reach4]

That is interesting ..why different sizes for cold and hot? Any other reasons besides the fact that one line has three fixtures while the other has just two?

Assuming no hot water recirculation, bigger pipe discards more water and takes more time to deliver hot water.

 

[Mini Me]

For the 3/4" PEX do I need to transition to 1/2" when I am branching toward the fixture ?
Here is my understanding of what you guys recommended me to do/use

Here is the part list
-ever 90 turn will be done using bend supports
-for the red line:
-it will be all 1/2 Pex B
-1 x 1/2 copper to 1/2 pex coupling-brass
-1 x 1/2 PEX tee -brass
-1 x 1/2 Pex to 3/8 male threaded adapter to connect the shower ◄ not sure about this one
-1 x 1/2-Pex x 3/8-in Dia. Chrome PEX x Comp Quarter-Turn Angle Valve for regular faucets
-for the blue line
-it will be 3/4 Pex B for the the entire line
-1 x 1/2 copper to 3/4 pex coupling-brass ◄ can't find this one, does it exist ?
-2 x 3/4 PEX tee
-1x 3/4 Pex to 3/8 male threaded adapter to connect the shower ◄ not sure about this one
-1 x 3/4 Pex x 3/8-in Dia. Chrome PEX x Comp Quarter-Turn Angle Valve for regular faucets
-1 x3/4 Pex x 1/2 brass male threaded adapter so I can connect the toilet

each corner turn will be done using a bend support
I will use support clips when traversing the studs
For the faucet stub out I am planning to use something like this

Am I missing anything else ?

edit: trying to source the above I am learning that there is no 3/4-Pex x 3/8-in Dia. Chrome PEX x Comp Quarter-Turn Angle Valve. Am I wrong ? This means I need to reduce the 3/4 PEX to 1/2 before the shutoff valve for the sink. And I think this is the same for the toilet end

 

[Reach4]

1 x 1/2 Pex to 3/8 male threaded adapter to connect the shower

Probably 1/2 to the shower-- not 3/8.
In the drawing (but not BOM), you show one 3/4 x 3/4 x 1/2 tee. I would use another with the 1/2 inch side port running to the toilet stop valve.

It looks like Snak, but is that Lav? I would run 1/2 to the lav cold. Maybe use a 3/4 x 1/2 x 1/2 tee to feed the shower and lav cold. Or make your first cold tee a 3/4 x 1/2 x 1/2 tee and use 1/2 downstream of that.

There are other possibilities, of course.

 

[Mini Me]

So the bottom line is that the fixtures should always get 1/2
..
To be honest this does not make a lot of sense for me my feeds are already 1/2 copper. I am transitioning to 3/4 pex for the cold, just for like 10f or less horizontally and the back to 1/2??

 

[Reach4]

So the bottom lone is that the fixtures should always get 1/2
..

Depends on what your valve wants, but 1/2 is most common. So typically you would transition somewhere, and 1/2 is enough for two common bathroom fixtures. The way you drew it up is perfectly fine, but for example, the toilet only needs 3/8. Toilet and lavatory stop valves commonly have 1/2 inputs, but 3/8 input can be had. If you ran 3/4 to near the stop valve, you would have to deal with that at the stop valve.

 

[Mini Me]

Depends on what your valve wants, but 1/2 is most common. So typically you would transition somewhere, and 1/2 is enough for two common bathroom fixtures. The way you drew it up is perfectly fine, but for example, the toilet only needs 3/8. Toilet and lavatory stop valves commonly have 1/2 inputs, but 3/8 input can be had. If you ran 3/4 to near the stop valve, you would have to deal with that at the stop valve.

not sure what part I can use to make the transition from 3/4 pex to 1/2 brass male threaded so I can connect the stop valve directly to it
Any suggestionss?

 

[Reach4]

not sure what part I can use to make the transition from 3/4 pex to 1/2 brass male threaded so I can connect the stop valve directly to it

https://www.pexuniverse.com/3-4-pex-x-1-2-pex-brass-pex-male-threaded-adapter-lead-free-brass

This would do exactly what you ask.

https://www.dahlvalve.com/products/...s/pex-F1807-crimp/supply-stops-611-PX5-31.php is an alternative, and is made in Canada. It still might be hard to find, because 1/2 inch is so much more common for supplying toilet stop valves.

I would run that section to the toilet in 1/2 inch instead. It's more flexible,plus 1/2, and even 3/8, pex has enough capacity to fill a toilet.

 

[Mini Me]

I also seem to have a problem to transition from 1/2" copper to 3/4 Pex :-((
I might be looking for a thing that does not exist: I am searching the above with a female adapter at the copper end
I really can't find anything that does that

Edit: found one but it is unavailable
https://www.amazon.ca/Copper-Pipe-Brass-Adapter-PXCA075-050/dp/B077QB862W

 

[Reach4]

I also seem to have a problem to transition from 1/2" copper to 3/4 Pex :-((
I might be looking for a thing that does not exist: I am searching the above with a female adapter at the copper end
I really can't find anything that does that

Edit: found one but it is unavailable
https://www.amazon.ca/Copper-Pipe-Brass-Adapter-PXCA075-050/dp/B077QB862W

https://www.supplyhouse.com/Bluefin...ale-Sweat-Copper-Pipe-Brass-Adapter-Lead-Free

Also, there are bushings that let you increase 1/2 inch copper pipe to 3/4: https://www.supplyhouse.com/Elkhart-30550-3-4-x-1-2-Copper-Bushing-FTGxC

https://plumbingonline.ca/products/sharkbite-u058lf can couple 3/4 inch pex to 1/2 inch copper with no soldering. It is possible to pull the plastic insert on the copper side for less resistance.