Pex Fitting Question

Thomas K

Thomas K

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Hi!
I am wondering if the Pex setup I installed yesterday will be okay for a shower, or if I should have used brass fittings which have slightly larger inner diameter. Both fittings shown in the photo are connected to 3/4" Pex lines. Two of the pipes go to sink valves, and unconnected ones shown will go to 36" shower. Single valve and single shower head.

I plumbed our other shower, and 1/2" ex worked fine. But I ran 3/4" pipe almost up to the shower valve and transitioned to a 3/4" x 1/2" plastic reducing coupling.

Please reply. I want to do this correctly the first time.

Thanks!

-Thomas
 

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I think I've decided, after reviewing the inner diameters of the various fittings available, to discard these plastic ones and purchase stainless steel fittings.
 
Looks like a PEX B install. My opinion, PEX A is more flexible as in running/installing the pipe. Better freeze protection as PEX A is made to be expanded. Full pipe size volume and pressure rates compared to PEX B, 40% lower. My book PEX B is substandard. Both PEX types require tools to install. Pricing is basically a wash. We are not talking thousands here between A and B. I see nothing that B offers that is superior to PEX A.

You mentioned stainless fittings. Boshart is the king. With their slow sweeping stainless 90's. They have a youtube video comparing PEX B hard 90's to their sweeping fittings. Boshart for the win.

My opinion on fittings. Stainless, poly or plastic then this lead free fake brass in that order.
 
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I went with Boshart fittings, but haven't decided on pex b. I can get Pex A sticks for almost same price as Pex B. If the Pex A sticks will work with B fittings, which I think they will. I will go with A.
 
The main restriction is in the fittings. PEX B fittings plainly just s_ck. LOL

I just had a total repipe in PEX A at my house. I had PEX B before at a couple reroute locations at home. Now with full PEX A and especially the outdoor faucets on full flow 3/4" PEX A lines, I have a ton of water volume and pressure. At my house there is now a huge very noticeable water flow conditional improvement. It's PEX A for the win. Going from 1/2" PEX B outdoor faucet piping to 3/4" PEX A is huge. All four outdoor faucets are now full port 3/4". I will never downgrade to PEX B for anything going forward.
 
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Thomas K said:
I went with Boshart fittings, but haven't decided on pex b.. If the Pex A sticks will work with B fittings, which I think they will. I will go with A.
Click to expand...

If you're going to use B fittings, my opinion is that you would be better off using B pipe.

John
 
There's .084 difference between .5 m copper and 5 pex tubing. Showers , bath tubs and outdoor faucets. I'd run 3/4" pex then reduce close to the valves. Anything device that uses a lot of water. 3/4" pex i.d. close to 9/16".
 
Boshart fittings are compatible with PEX A. When it comes to working well in tight spaces, or when you need to make a lot of bends, flexibility really matters. Since costs are really close, I would go with PEX A as well. Just make sure you’re using the correct tools for the PEX grade since the crimping and clamping tools are specifically made to work with certain types.
 
Just remember if you choose PEX B, must up size your pipe to "attempt" equal flow of PEX A.

You would need a 1" PEX B pipe to try to be equivalent to 3/4" PEX A in volume and pressure.
 
Slomoola said:
Just remember if you choose PEX B, must up size your pipe to "attempt" equal flow of PEX A.

You would need a 1" PEX B pipe to try to be equivalent to 3/4" PEX A in volume and pressure.
Click to expand...
The difference is not that big, but you can't get 7/8 PEX. ;-)

Going to brass or stainless fittings can make the flow better with PEX B than with plastic fittings with PEX B.

For PEX A, both plastic and brass common fittings are ASTM F1960

Types of PEX Fittings and Connection Systems

Overview of major PEX fittings and connection types. Compatibility with other PEX connection systems. PEX Tools and other components required to make a proper PEX tubing installation.
pexuniverse.com pexuniverse.com

I also see they list Press for PEX.
 
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Reach4 said:
Going to brass or stainless fittings can make the flow better with PEX B than with plastic fittings with PEX B.
Click to expand...
What??? PEX B fittings are PEX B fittings. Poorest flowing piping out there. I must of missed something?

I went from 1/2" PEX B outdoor faucet plumbing to 3/4" PEX A. Huge difference out of a 125 foot long garden hose. That is basically 2 steps up in volume and pressure.
 
Reach4 said:
Hotdogs are hotdogs. Cars are cars. https://en.wikipedia.org/wiki/Pigs_Is_Pigs Look at the link I posted in #12.

F2159 is smaller inside than F1807.

Also see https://terrylove.com/forums/index.php?threads/how-much-do-pex-crimp-fittings-reduce-water-flow.90910/#:~:text=An F1807 1/2" coupling has an equivalent length,be a reduction in 9.5' of equivalent length.
Click to expand...
Thanks for the info. All I know is what I had at the house. PEX B is not even close to PEX A. I'll just leave it at that. I think it's well known you must upsize PEX B to be the same as PEX A. Watched numerous videos on it, which must be true. LOL ;)
 
You must upsize PEX A to be as good as copper size-wise.

PEX B fittings have some advantages. Less expensive. Sometimes the tools are much easier to fit into the available space. There is more variety of fittings readily available. That said, I have only used PEX A and expansion fittings so far with PEX.
 
Pex A is for domestic water Peroxide method (used to make PEX-A tubing)
Pex B is for heating Silane method ( used to make PEX-B tubing)
 
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