Copper to pex piping

I noticed in a home that there was about 90 percent copper supply lines in the home. There were some piping that was pex. I am not sure but I was always under the impression that oxygen barrier pex was primarily used for boiler heat systems. This pex was about 20 ft. long connected from a copper supply line to the hose bib at the exterior and there was labels on the piping depicting oxygen barrier pex. Is this ok? I recommended to my client to have a qualified plumber to give his professional opinion.


yes thank you but I found this also

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Without supplying any markings on the pipe such as ASTM F876 for approved materials in water distribution piping, it is impossible to know. Generally it’s not but contact a local plumbing contractor as every jurisdiction is different.

It is getting very common here now.

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Thanks Larry that was great information!!

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It’s been popular around here for a few years now. Plumbers love it because it bends, cutting down on installation time.

In Phoenix you can’t buy a new home with copper pipes. The shark fittings can be used on copper and PEX pipes

Oxygen barrier PEX is just fine.
This is used in in-floor radiant applications specifically to keep oxygen from getting in the boiler water which causes premature damage to cast iron circulator pumps. Also, the whole idea with any boiler system radiant in-floor or not, is to keep air out.

So it looks like it can be used in a homes domestic system. Good to know for the next inspection if I see it.

Domestic heat or water distribution. I don’t see where this type of PEX is an approved material for domestic water distribution maybe somebody can show me where that information is. This is what I could come up with but maybe someone has something saying it’s approved for domestic water as well. Seems a few members are running into this on a regular basis.

ASTM F876: Standard Specification for Crosslinked Polyethylene (PEX) Tubing.
ASTM F877: Standard Specification for Crosslinked Polyethylene (PEX) Plastic Hot- and Cold- Water Distribution Systems.
ASTM F2023: Oxidative resistance of PEX to Hot Chlorinated Water per NSF protocol P171 (Non-Barrier PEX Tubing).
CSA B137.5: Crosslinked Polyethylene (PEX) Tubing Systems for Pressure Applications.
NSF/ANSI 14, nsf-rfh: Evaluated for use in Radiant Floor Heating (NSF-rfh) Applications (Oxygen Barrier PEX tubing).
NSF/ANSI 61-G, NSF/ANSI 372, nsf-pw-g: Complies with NSF/ANSI standard 61-G for Lead-Free Drinking Water System Components (Non-Barrier PEX Tubing).
UPC listed by IAPMO (International Association of Plumbing and Mechanical Officials).

This is all I found, Martin:

Most oxygen-barrier PEX does not have the appropriate approval codes for use with potable water and should not be installed in domestic plumbing applications. Uponor’s hePEX recently received NSF approval, making it one of the few types of oxygen-barrier PEX on the market that can also handle domestic water.


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Leave it up to Uponor they are top shelf material.

In this article it says you can use it

James the website is coming up as a red flag on my Norton software. I tend not to put much merit in articles and prefer published code books for reference instead. NSF ANSI 14 can be found under ASTM F867. If the pipe has either of these markings it may be used for domestic water distribution according to the international building code. But simply having oxygen barrier PEX without this identification does not mean it may be used for domestic water distribution. Like I always recommend contact your local licensed plumbing contractor if there’s a question

This is the NSF certifying organization:

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Looking for this.

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