Confused About the Various PEX Fitting Types

Last year I installed my EKO 60 with 500 gal of storage by myself, using rigid copper, except for one underground PEX line running to a second house. This year, I finally hope to find the time to improve the heat delivery part of the system, planning to plumb in radiators and finned tube baseboard to gradually replace the plenum HX's, so I can get more flexible zone control and better heat delivery with lower water temps.

Anyway, I am planning on using as much PEX tubing as I can for the various plumbing jobs ahead. I have become totally confused at times with the myriad of different PEX manufacturers and fitting types. I bought the Wirsbo expander tool last year (used, cheap on EBay) and was planning on using the Wirsbo PEX tubing again. However, I am finding so many other choices for tubing and fittings out there - crimp systems, shark-bite style, etc. all of which seem to be limited to working only with certain brands of tubing.

I also have to do some regular household plumbing for the hot water tanks, etc. and for these I will use non O2 barrier tubing. I saw some nice Vanguard press-type fittings at Lowes that were expensive, but easy to use.

This is a tall order, but can anyone give me a big-picture overview of the main families of PEX fitting types available, and whose PEX tubing they are inter-compatible with? Before I start on this next major phase of the heating project, I want to make sure I understand the various options open to me in selecting the best PEX system to use.

Make sure you do your homework first. I can't answer your question entirely, but maybe I can help shed some light with problems I've had in the past. There is pex then there is pex-al-pex. Most pex with or without o2 barrier is interchangeable. Pex-al-pex is a different animal. Make sure you buy from a good name brand company. I have just over a mile of 5/8" I-pex brand tubing and fittings, both in floor and concrete. The company no longer makes or warranties their stuff. I have some pex-al-pex delaminating and fittings that have gone bad (or dezincified).

I use Wirsbo's material and fittings, although I have worked with other stuff for other people by request; I have not been very impressed with most of the other make fittings that I've worked with, which seem less robust in design and construction.

For my own use, the only thing I'd want to use is a pex-a based tubing, and fittings that I know are made by a company that's been in/focused on pex and will be staying in/focused on pex. Wirsbo isn't the only one in that category, but they're about as solid as you can get -- and, in my region at least, much more widely and readily available like Viega or Rehau.

The cost and grief of re-doing something that fails, in my opinion, dramatically out-weighs the gratification of short run savings.

some good prior threads on PEX:

http://www.hearth.com/econtent/index.php/forums/viewthread/22799/

http://www.hearth.com/econtent/index.php/forums/viewthread/36799/

The tube, fitting, and ring all should have standards printed on them.

ASTM F 876 is a tube standard
ASTM F 1807 is a fitting standard
SDR 9 standard dimensional rating refers to the tube dimension

If the tube has this standard, and the fittings and rings have the standard then they are compatible.

Companies like Sioux Chief build fittings and rings that are warrantied to work on all brands of the correct standard.

Now, the question arises.. will the manufacturer warranty failures if you use a fitting other than the one the sell (although SC builds fittings for many brands

Other types of tube like PAP or Viega FostaPex may have other standards and require a fitting specific to their brand.

I'd caution against imported fittings, without ratings.

hr

"Shark bite" style fittings, or push-on fittings, even sold at big box stores, will fit most PEX. The exception here is pex-al-pex, which is PEX with an aluminum sheathing, which is thencoated in another thin layer of plastic. Viega Fostapex is a good example of this. The advantage of PEX-AL-PEX is that it is more rigid and requires less anchoring. The disadvantage is that it requires a proprietary-made drill-mounted tool to strip the plastic and aluminum sheathing off. Once this is removed, shark bite fittings will fit, though it's always better to use fittings made by the same manufacturer as the tubing. PEX manufacturers tend to have their own proprietary fittings, that require a proprietary crimp tool. The tools are where the cost is, more often than the materials when working with PEX.

In a pinch, I have made repairs to Viega Fostapex by using sandpaper to get off the extra sheathing, and using a sharkbite style connector that is capable of joining PEX to copper.

I was hoping that you guys could also comment on the easiest way to go from 1.25" PEX to CU (copper) pipe. I can't seem to be able to find 1.25" PEX fittings at any of the on-line hydronic suppliers. I can't invest in a specialized tool like the Watts radient power crimper for the few fittings I need to do. Also, the SS cinch rings max. out at 1". I do not mean to hyjack this thread, it just seemed to fit in well with the orig. post.

Ford Meter Box Company www.fordmeterbox.com makes fittings for PE and PE to copper, underground pipe connections. Not sure what the temperature rating is.

hr

something like this?:

http://www.pexsupply.com/Viega-62070-1-1-4-PEX-Press-x-1-1-4-Copper-Tubing-Adapter-5852000-p

fyi - this was the second result on Google when I input search terms:

Code:

 1 1/4" PEX 

thats exactly what I don't need. A fitting that requires an expensive, specialized tool for a few fittings: "The Viega PEX Press connection system requires a Viega PEX press tool, Viega Press Sleeves, and Viega Press fittings"

Sorethumbs:

All pex requires a specialized tool. It's just how the game is played. If you don't want the Viega PEX press system, you will need to get the ProPex expansion tool and fittings. If you don't want that, you will need to get the HydroPEX fitting system, crimp tool, and rings.

Pex is easier to install, safer for drinking water, more temperature and freeze resistant than other types of piping. Materials may also be cheaper. However, the overhead for the tools you need to work with it is large.


Boilerman,

This website breaks down the three main types of fittings and what tubes they can be used with:

http://www.pexsupply.com/PEX-Fittings-525000

Click on the "Comparison guide" for even more info.

What? That's crazy talk. Shark bite's work. I've also seen compression fittings that work. Neither of those require a specialized tool. Problem is - I can't find them for 1.25".

I have a crimp-ring tool that's good up to 3/4" PEX and a cinch tool for the SS cinch rings so I'm somewhat familiar with working PEX up to 1". 1.25" is a whole diffrent ball-game for me, and I'm not goint to invest in a $$$$$ tool for a handfull of fittings. I'm sure they exist, just need to find them.

ok Sharkbites do work, but sharkbites and comp fittings just seem like shortcuts to me. I try not to take shortuts.

wonder if you can rent
leaddog

Just a note about fittings........Viega fittings are, and always have been manufactured from bronze not brass as just about everything else is to my humble knowledge. This is a matter of no little importance from a long term reliability standpoint. If you are familiar with boats used in saltwater environments you probably know that the fittings in direct contact with the briney deep are either stainless steel or bronze due to their durability in harsh conditions. My vote would be for Viega but the required power tool is an impediment. I would suggest you try to find a plumbing supply house that carries the brand and see if you can rent their press tool if you source the fittings there. I rent/loan mine out, depending on the associated sales volume, about every week.

As far as sizes go and what fits on what; if the tube is ASTM 876/877 any pex fitting will fit. That's not to say that some methods are not better than others.

Boilerman:
You say you purchased a Wirsbo expansion tool. That means you are going to use Propex parts only!

I would strongly agree that the Wirsbo fittings and tubing are well worth having. Just be sure you stick with the Propex. It can get a little tricky because most of the other brand stuff are crimp connections, which are smaller in size and won't work with the expansion tool. Even Wirsbo has a crimp fitting line, just remember to order Propex parts. Ferguson in my area sells Wirsbo parts, they will provide you with a 200 page catalog.

I have not use crimp connections so can't say a lot about them. I have used Propex for over ten years and it does a very nice job. There are a couple of tricks to it, but if you take the time to read the Wirsbo instructions you won't have any problems. (fyi, in using the expansion tool you will find it is easy to make 1/2" pex connection, 3/4" is no problem, 1" is difficult (takes a lot of power to expand 1") challenging).

As too "shark bite", I would not use those quick slip together connections. For me they do not react well to mechanical stress.

I went through this with 1 1/4" fittings for Rehau pex about a year and a half ago. Finally I tried the one inch clamp type fittings used for plastic well pipe readily available at Home Depot. Either brass or steel. Worked like a charm! Cost about $5.00 each. I thought making 8 connections was going to cost me a fortune in tools. In the end it cost about $40.00.

RE Wirsbo/Uponor and Rehau; The expansion type fittings used for those brands will not interchange on other types of pex. They WILL accept insert type fittings that are used on other brands of pex.
Uponor and Rehau are type C pex (if I recall correctly) which means that they are crosslinked with an electron beam process. This gives the tube a "memory" that allows it to be expanded (via the special tools) and return to its original dimension thereby tightening itself around the fitting. Pex made using the A or B method does not have this memory feature and will likely cause problems if used in that manner. Dimensionally, all pex bearing the ASTM numbers referenced above is the same. Therefore, a Viega fitting for example will fit and work in Nibco, Uponor/Wirsbo or whatever brand you can name. The expansion type fitting systems however will only work in type C pex.

Heaterman, I couldn't remember either so I looked it up, here is the skinny:

Wirsbo/Uponor is a Pex-a manufacture. It has a higher degree of cross linking, said to be around 85% compared to 60-75% for Pex-b and Pex-c.

The all have expansion memory, however the more cross linking the better the memory. I am sure Wirsbo would want their customers using their pipe, Pex-a.

I have used Pex-a and some Pex-b. Pex-a is a lot nicer to use.

http://www.uponor-usa.com/~/media/Files/Product Documents/PEXtubing_FactSheet_06.aspx?sc_lang=en