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[Daped01]

In doing research on boiler lines, i've come across both pex and pex-al-pex.  Can someone tell me the difference in the two?

[MattyNH]

Here's what I know, pex al pex has an aluminum sleeve sandwiched between the plastic (pex) inner and outer sleeves, the aluminum is an oxygen barrier and is important for keeping oxygen out from pressurized systems, either can be used in unpressurized systems, the fittings do not interchange and the inside diameter is a little bigger for pex al pex.

your right..it is a little bigger.Pex-al pex is a true inch (inside diameter of the pipe)

[RSI]

It is actually slightly larger than 1" ID. You can get metric pex that is the same size.

[Daped01]

ok, so what i'm reading is its a difference in diameter size?  Am I going to want to buy my pex before I start buying fittings to make sure I buy fittings that fit the pex?

[Daped01]

so are you saying each tubing manufacturer sells fittings also? 

[RSI]

The crimp ring or push on fittings (like sharkbite, probite, etc) will work on any CTS pex. (standard size)
There are a few types of fittings that are only meant for use on certain brands. They use an expanding tool and are a little larger inside. You likely won't be using this type unless you know someone with the tools because they aren't cheap.
If you use Pex-al-pex you will need to use pex-al-pex fittings, not pex fittings.
If you use metric size pex such as Logstor you will need probably want to buy the fittings from the same place you get the pipe. I have heard that you can use pex-al-pex fittings on it but never tried.

So, you will want to decide what pipe you will go with before buying the fittings.

[Jeff]

Daped01,

It can be a bit confusing, even for me, and I deal with this question all of the time.

The ID of 1" pex is .875", the ID of 1" pex-al-pex is 1.032". The actual metric size is 26/32 mm referring to the ID/OD dimensions. 

This compares well to 1 1/4" pex which has an ID of 1.052". For this reason many choose it when flow is important.

IMHO, for the cost, pex-al-pex insulated pipe has a better cost to BTU delivered ratio. It is more expensive than 1" pex but considerably less than 1 1/4" pex. But of coarse only a portion of installs need anything more than 1" pex. So no reason to upgrade for most.

The fittings are more costly so factor that in.

Some like it because it stays straight or bent when positioned.

Almost all of it, including ours, is imported from China.

IPEX who used to make it in North America left the business in 2009 and refuses to return. I have tried to convince then even writing the CEO to no avail. Though I did actually get a nice letter in return.

I hope this helps.

Jeff Zack
Owner,
Z Supply, LLC
www.z-supply.com

[atvalaska]

pex-al-pex stays bent when bent...I have "warm board"  flooring ,,, muiti cor is what I have "the best>pex al pex from my research...and higher priced.....spending more money don't make something better...but this mite be diffent this time   imo of course