Dura-Pex vs copper pipe

[kmdigital]

After seeing a new house plumbed with PEX, I've decided to never use anything else again! Really neat to work with. My question - I got some from Lowe's for a small project, and chose the "slip-in" fittings which don't require a crimping tool. Have I made a bad choice?It sure looked like an easy installation, but hasn't been done yet - if I should go back and get the crimp style fittings, I can still do so. Any suggestions?

These fittings are supposed to be ok for this purpose, but personally, I don't think I would install them in a wall where they aren't easily accessible. Not to mention, that these fittings are very expensive for what you get, about $5 for a 1/2" tee. They work great though for copper repairs when you can't get the dad-blamed water to stop dripping out, even with bread, etc!

My concern with these slip over fittings is with any pipe material that gets softer as it gets hotter, such as PEX. Like I say, they say it is ok for this purpose, but...... They work great with copper or CPVC though, but they are pricey.

 

[gordon21]

One more question about the PEX slip joint fittings. It seems as though they rely on O-rings as a sealing device. What about the deteriotion factor of rubber O-rings? I would hate to see them fail after about 5-10 years and suddenly have water leaks all through the house inside walls and in the attic.

I am old enough to remeber the fiascos with the plumbing pipe they used in trailers 15 years ago and also the Masonite (??) siding mess.

Both of those items seemed great when released, but the negatives popped up their ugly heads years later.

Would it be better to use the crimp PEX or the slip joint PEX fittings? Cost is not a concern.

 

[river rat]

One more question about the PEX slip joint fittings. It seems as though they rely on O-rings as a sealing device. What about the deteriotion factor of rubber O-rings? I would hate to see them fail after about 5-10 years and suddenly have water leaks all through the house inside walls and in the attic.

I am old enough to remeber the fiascos with the plumbing pipe they used in trailers 15 years ago and also the Masonite (??) siding mess.

Both of those items seemed great when released, but the negatives popped up their ugly heads years later.

Would it be better to use the crimp PEX or the slip joint PEX fittings? Cost is not a concern.

I agree that cost is not the primary issue - while I'm certainly not "made of money", I DO value time, and it looks to me like the slip fittings would save enough time to balance the extra cost, IF THEY WORK AS WELL.
Looking at the sealer rings - they aren't "O" rings per se, but are a tapered sealer ring, which looks like it would seal better as more pressure is applied.
Also, they appear to be nylon (or a similar material), rather than rubber.
I'm an optimist about new technology, too, and appreciate the fact that there are always people out there who are trying to invent a better mousetrap. I just don't wanna get MY tail in it!

 

[kmdigital]

Generally, o-rings don't leak even as they age, until they are moved. Then nothing you do will stop the leak. Example is the Nibco gate valves from the early 80s. They had o-ring stem seals instead of adjustable packings like most other valves. They worked great for a few years, and in places where the valve is never closed they don't leak, but whoa is you if you turn the handle on that valve after it has set for about 10 years. It is almost guaranteed to leak, and nothing will stop it short of disassembling it and replacing that blasted o-ring.

I like the crimp fittings much better, both due to cost and the fact that it isn't relying on a rubber o-ring to create a seal.

 

[neilly2]

The connections weren't complete as of that picture. Most of the block is filled now. The sizes are 3/8" to bathroom sinks and toilets. 1/2" to showers, tubs, kitchen sink, laundry etc. 1" feed to block. Flow is excellent.

One thing I forgot to mention is that you get hot water a lot quicker with the direct line. In a regular copper piped house, you would have to clear the entire 1" or 3/4" main of cold water before you get hot. The regional sales rep for Vanguard checked out our installation and estimated is would take 4 seconds before we get hot water. I thought he was high, but I'll be damned if within 4 seconds the water starts warming and is fully hot within another 2. And I'm the first shower of the day.

 

[Raspy]

I've used a lot of PEX tubing. Here are some things that must be kept in mind.

PEX is not UV rated and must be kept out of the sun. Do not use it in a collector or outside.
It is rated at 200 degrees at 100 PSI. Solar collector return temps can melt it, use copper for collector return lines and drain back lines.
The best connectors are crimp ring connectors with brass barbs. I don't like the "O" ring style push on connectors. If you use a ferrule style connector you must use a tube insert. But crimp ring is best for most appliations.
The old plastic pipe problems from some years ago were with polybutalene piping connected with plastic connectors, PEX is different.
For radiant heating use the system should be closed loop. This protects the tubing from chlorine, runs it at a lower pressure, allows the use of iron parts in the system, and prevents other corrosion issues. However, if you do run iron parts you must use oxygen barrier PEX and/or a good inhibitor.

Wetspirit

 

[varmint]

This is not exactly about PEX, but it's of interest here, I think. My brother manufactures (a lot) equipment for geo thermal, mostly pump modules and special valves for loop installation. He makes brass valves, plastic molded valves (plastic, but very high tech) and precision cast brass valves. This stuff can't fail or leak, or his company will have a problem. They still sell valves with threaded fittings, since some old time installers feel more comfortable with that type, but most of the valves and modules that go out use a propietary O ring push in connector. This is a time-tested European system, and they actually have fewer problems/ returns with O ring units than they do with the threaded. The O rings have a proven performance life, and the leak rate is lower! Go figure. Of course, lots of PEX goes into geo thermal systems as well. As an architect, I've seen lots used for under-slab radiant heating and plumbing, never a problem. Copper can have issues with water chemisty and I've seen pin hole leaks caused by improper electrical grounding when the water line was part of the earth ground system.

 

[mudcat]

Intresting Varmit. Could you explainmore on the improper grounding?

 

[dfkrug]

I took my wife to go look at the PEX stuff at Lowe's yesterday. A new clerk says the stuff is great except you can't put the fittings inside walls!!! What good is this system if all the fittings have to be out in the open somewhere? OR, is this guy informed wrong?

I believe they meant that all connections must be made in an accessible
junction box or at the valves. Leaks will only occur at these locations,
if at all. Same rule applies for the CSST tubing used for gas lines.

I remember installing PEX water coolant lines for superconducting
magnets at a cyclotron lab more than 30y ago. Good stuff.

 

[varmint]

Mudcat: what I meant by grounding was that the copper house piping was used for an electrical ground, but it wasn't actually grounded, since the supply line had been changed to plastic at some point, which left the copper piping connected to the electrical system without being grounded. I don't know why, but once we ran a proper ground connection to a new ground round, the pin-hole issues went away. I don't know, but perhaps the NEC doesn't allow water pipe to be used as a grounding connector anymore?

 

[_RaT_]

Mudcat: what I meant by grounding was that the copper house piping was used for an electrical ground, but it wasn't actually grounded, since the supply line had been changed to plastic at some point, which left the copper piping connected to the electrical system without being grounded. I don't know why, but once we ran a proper ground connection to a new ground round, the pin-hole issues went away. I don't know, but perhaps the NEC doesn't allow water pipe to be used as a grounding connector anymore?

I suppose it may vary per locale, but here we still bond water pipe not for achieving a ground via the metal plumbing be it copper or galvanized but to ensure that if a hot wire ever touched the pipes it would not become energized and a potential shock.

Are there some more recomendations for internet order for PEX tools and supplies? This has been a great post one that interests me and my older galvanized plumbed home.

 

[_RaT_]

Here is a house I toured and took a picture of the installed a Manabloc.

 

[AlanB]

Just checking myself a bit here.

Is there a downside other then initial cost of tools to using this PEX?

Lowes currently has some tools on Clearance which I was thinking of picking up.

Looks like an excellent system from my perspective, not sure how it will be to "patch in" in 10 or 20 years when the pex is harder and more brittle though, but all I am really seeing is the initial cost of tools, and I am only seeing that at about $200 to $300 unless I have missed something.

Very interesting topic for me.

 

[_RaT_]

Just checking myself a bit here.

Is there a downside other then initial cost of tools to using this PEX?

Lowes currently has some tools on Clearance which I was thinking of picking up.

Looks like an excellent system from my perspective, not sure how it will be to "patch in" in 10 or 20 years when the pex is harder and more brittle though, but all I am really seeing is the initial cost of tools, and I am only seeing that at about $200 to $300 unless I have missed something.

Very interesting topic for me.

My understanding is that it has been in use in Europe for quite a few years, decades even. As long as it remains out of UV, it apparently has a yet to be determined lifespan. I know for a product like PVC pipe, the lifespan for underground use is not really a factor, it far exceeds the life span of the appurtanances (valves, fittings, etc).

 

[AlanB]

Do the different brands PEX tools work on other brands fittings etc. or do I have to buy abc tools to work on abc fittings?

 

[ktm250rider]

Do the different brands PEX tools work on other brands fittings etc. or do I have to buy abc tools to work on abc fittings?

No, you have to get the correct tubing, fittings and tools. The type I used uses a PEX expansion ring with a barbed fitting. The tool enlarges the ID of the PEX pipe and ring. Its then slid onto the fitting. Due to the PEX memory, it returns to its original diameter creating a water tight seal.

 

[kmdigital]

No, you have to get the correct tubing, fittings and tools. The type I used uses a PEX expansion ring with a barbed fitting. The tool enlarges the ID of the PEX pipe and ring. Its then slid onto the fitting. Due to the PEX memory, it returns to its original diameter creating a water tight seal.

This is only true for certain brands. Wirsbo ProPex requires specific fittings and tools, but most other brands are 100% interchangable.

 

[Kays Supply]

I just installed several hundred feet of Nibco brand PEX today. It has it's own tools. The warranty is far less if you use other brand fittings or tools. The 1" PEX from Nibco is a problem. They don't have a tool to install the crimp rings. I have to use Zurn rings with Nibco fittings. The Zurn tool is totally different. The Zurn system has one up side. You use one tool for 3 different size rings.
I am in Illinois. Illinois is the last state in the US to approve PEX. It has been a slow process and not up to speed yet.

 

[kmdigital]

I am in Illinois. Illinois is the last state in the US to approve PEX. It has been a slow process and not up to speed yet.

The real problem in IL is the unions. They control everything, especially in Chicago, which is why Chicago still requires bell & spigot cast iron drain lines for all commercial jobs, and some residential. Talk about extreme amount of labor to install this stuff, something that fell out of favor in the rest of the country 50 or more years ago! It's all about creating as much labor as possible to protect union jobs, and Chicago is a very, very strong Democratic and union city.

 

[srossman]

Here is a house I toured and took a picture of the installed a Manabloc.

_RaT_
Did by any chance you see if the PEX tubing went into the Tankless hot water heater? I just had one of these installed, and they used coppper coming out of the tankless unit to mate to the plastic cpvc in the rest of the house.

Thanks,
Scot