Best PEX system?

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Nukedaddy

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I am coming back to the plumbing industry after 15 years in Nuclear Power. There have been a few changes. PEX seems to be the #1 potable water material but I have a few questions before I commit to a specific "brand".

Are the "insert" types of fittings compatible? For example, will a "Sharkbite" insert coupling work if crimped with a Nibco ring? If the tubing is the same for all brands under the ASTM standard, should not all the fittings work as well?

Are there any known incompatibilities between fitting brands? Are there any known issues between brands of tubing and fittings?

Are there issues known about OD fittings (push-on)? Is the tubing OD controlled or ID controlled or both during manufacturing?

What is your (everyone's) favorite line of PEX tube and fittings for potable water?

Some codes (like Illinois) are rather picky about using insert fittings for potable water. (The assumption is that the reduced ID of the fittings might starve fixture supply.) Does anyone oversize branch supply line sizes to compensate? Also, the resilience of PEX should likely make the use of air chambers and shock arresters no longer necessary, true?

Thanks for taking the time to share your recent experiences and knowledge.
 
As far as pex is concerned, any product is the same. I've used zurn and viega myself. I would stay away from shark bite brand myself. Just never used the stuff.

I do like the sharkbite fittings only for spots with no access.
 
I am moving towards PEX and away from CPVC myself, so I have done a bit of research on this very subject.

The general trend in my area is towards Wirsbo Uponor PEX, with the expansion system. The Uponor expansion system has a couple of attractive advantages. First, there are no crimp rings, no need to worry about crimp tool adjustment, forgetting to crimp a ring, gauging a crimp, etc. Also, the ID of the fitting is larger than crimp, as the pipe is stretched to slide over the fitting. So at first impression, this should allow more volume, flow, and pressure at the fixture. Also, the fitting are plastic, which should eliminate metal corrosion and fatigue as possible failure points. Also, the tools to make an expansion joint are expensive and not available in the average hardware store.

Cons that I have identified. The fittings are plastic, and we all know how well that worked out with polybutylene pipe using plastic fittings. Crimp fittings can be pressurized to full test pressure immediately, whereas expansion fittings need some time for the pipe to shrink back and make a good seal against the fitting. Fittings are not nearly as available as are crimp fittings, so when you are in the middle of a repipe on a Saturday, and you find that you are fresh out of 3/4" x 1/2" tees, you will still have to settle for a crimp connection tee from the nearest Home Depot. Also, the tools to make an expansion connection are expensive, and not readily available.

Crimp fittings are available everywhere, work with any kind of PEX pipe, including Wirsbo, can be pressurized immediately, can be mixed and matched between different brands of pipe, fittings, and rings, are really quick to install, and the tools to install them are readily available at a reasonable price. Crimp fittings seem to have withstood the test of time, and I have only been able to find one case of a crimp fitting failing. It appears that the water chemistry attacked the brass crimp tee, and the tee broke apart. Note that I am not including the rather well known and spectacular dezincification problems that have been noted with some area's water.

Cons include the fact that the tools, rings, and fittings are widely available. Also, the fittings are metal, and therefore are prone to failure if the local water is really aggressive. And, since the fittings fit inside the standard ID of the pipe, they will tend to reduce flow. It can also be a bit of a pain to get crimpers in tight spots, or certain crimpers close to certain fittings.

I have managed to find accounts and pictures of exactly one crimp fitting failure (minus dezincification failures) and exactly one plastic expansion fitting failure.

PEX pipe itself is a different story, there are well documented cases of the pipe itself failing for no good reason. This does appear to be limited to certain brands and manufacture dates of piping, so I think in general it is a good system.
 
phishfood said:
Cons include the fact that the tools, rings, and fittings are widely available. Also, the fittings are metal, and therefore are prone to failure if the local water is really aggressive. And, since the fittings fit inside the standard ID of the pipe, they will tend to reduce flow. It can also be a bit of a pain to get crimpers in tight spots, or certain crimpers close to certain fittings. I have managed to find accounts and pictures of exactly one crimp fitting failure (minus dezincification failures) and exactly one plastic expansion fitting failure. PEX pipe itself is a different story, there are well documented cases of the pipe itself failing for no good reason. This does appear to be limited to certain brands and manufacture dates of piping, so I think in general it is a good system.

I have seen plenty of rings fail over the years, the stainless steel cinch rings either bust when tightening them too fast, or if your tool is not calibrated correct it won't close them tight enough to seal properly. The copper ring style have the same calibration issue plus they take more time to remove. Up honor wirsbo with the expanding ring take time to close after doing a joint, but is nice that it can go upto at least 1-1/2" pipe and fittings.

Every system has its issues, Kytec was a wonderful pex product until it got pulled. The nice thing about pex it will expand a little in cold weather unlike most metal piping systems.
 
I wasn't even including the cinch ring system, I took one look at those and thought "Really? You have GOT to be kidding me."

The calibration issue can be a concern, but if you are gauging finished crimps on a regular basis, you should catch it before the tool gets way out. One thing that I see with the expansion system is the size of the completed joint. What with the double thickness of pipe, and the larger fitting, there would be no way that would fit in the 3/4" space that is common between exterior block walls and drywall that is so common in my area. The crimp fitting snugs in there quite nicely.

BTW, send Chris or Austin a PM, they can let you into the Professional section of the forum.
 
Hey everybody, sorry for posting in an old link I just have a few questions I need answered, and This looked like a good place to post them. Im intersted in PEX tubing and setting up a system in my home with it before winter time comes around. Im considering going the mainofld route and using oxygen barrier tubing from what I've read. I just have a few questions that i would like to have answered by professionals.

What type of PEX is mostly suggested, and whats the difference between types A, B, and C?

Does the big name company selling the PEX make different PEX than the small time company?

Which type of connections and fittings are suggested by the experts? Poly or brass?

Dont want too overload with questions from the start, just getting a few answers would really help me out. Thank you.
 
There are somewhat scattered reports of issues with PEX pipe failing, and for the most part they seem to be brand specific. Meaning that some manufacturers seem to be having trouble with their pipe, and others do not.

I, personally, am not comfortable with crimping or otherwise compressing around plastic fittings, so I stick with brass. I am also somewhat uncomfortable with the higher zinc content in today's lead free brass fittings. So my preferred fitting is Viega PEX Press bronze. These require a special tool to crimp. The tools are expensive, and the fittings are really expensive.
 
When im using pex i use viegas red and blue pex and viegas polypex fittings, they are crimp fittings and i have never had a problem with them. Ive used it in muiltiple applications with no problems. They are cheap and havent had a problem with them, hope i could help, good luck
 
When im using pex i use viegas red and blue pex and viegas polypex fittings, they are crimp fittings and i have never had a problem with them. Ive used it in muiltiple applications with no problems. They are cheap and havent had a problem with them, hope i could help, good luck

Please post an introduction thread so we could give you the welcome you deserve.
 
I just replaced the water main from the water meter to the house . Used 1" PEX , brass barbs & the black copper crimp ring .

It has only been a couple of weeks , but so far , so good . Praise the Lord !

God bless
Wyr
 

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