# A,B,C s of pex



## eaglei (Sep 21, 2012)

The different grades of pex are apparently not in that order . When it comes to oxygen barrier pex used for in slab radiant heating . Every grade is cross linked by a different method by each manufactuar . What i have learned over the years is that pex-a by upinor (wirsbo) is the original pex and most flexible . Followed by pex-b which is manufactured by several companies .Then there is pex-c a fairly new comer manufactured by only a few companies . So when i searched pz i found this was not what i was taught . Some stated that pex-c was far superior to pex-b . That is when i did some research on-line and basically what i found is that everyone agreed to disagree . :yes: Seams like plumbers know it one way followed by supply houses and finally manufacturers . Now I'm totally confused . The only thing that i found that they have in common is that they have to meet the same standards . :laughing: Any input would be greatly appreciated . Thanks Ken


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## plbgbiz (Aug 27, 2010)

When in doubt, stick with Uponor.


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## Will (Jun 6, 2010)

I personal feel Wirsbo is the best manufacture of PEX piping. I don't believe there connection system is any better than crimping with a copper ring though. I've had to opportunity to use a lot of different types of PEX systems as I used to do a lot of custom homes. All systems have there advantages over the other, but one thing I have found is that the copper crimp will not leak. Ever. I've done literally thousands of copper crimps, and I've never had a leak. Can't say the same about Wirsbo expansion or the SS "cinch clamps". Both of those systems I had leaks on or had to do repairs on. 

Wirsbos main drawl back is you can't loop it under the slab with a manifold system(like you would do with soft copper). With Wirsbo you have to have so much space between fittings that a manifold would be way to wide to fit in a stud cavity. With a copper crimp system you can install PEX under the slab the same way you could have done soft copper. Another drawl back with Wirsbo is that you have to use a heat gun when installing it in the winter. 

I use only PEXa(wirsbo) or PEXb. I stay far away from PEXc which is by far the worst. PEXc is rarely round, usually egg shaped, and it has had issues with the piping "splitting". 

As long as you use USA crimp fittings and use a good crimper (I use Mil3 crimpers) I feel that it is the best, longest lasting, and lest likely to ever fail. You can use either PEXa or PEXb with that system. Wirsbo is a a great option also, but I have had leaks with it, and the drawl backs with it make me use copper crimp connections.

BTW, can't speak for other manufactures, but Sioux Chef crimp fittings will still be under warranty with Wisbo/Uponor piping.


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## Protech (Sep 22, 2008)

Pex a has the lowest chlorine and UV resistance out of the 3.

Other than slightly increased flow rate, I can't think of any real world advantages of pex a. Which is offset by it's increased material and labor costs IMO.

I stick with pex b unless I'm working with RO water. In that case I use pex b. I have used all 3 types. I dislike pex c as the cross-linking is not uniform.

Millions of crimps installed to date. No call backs. I put a 25 year warranty on my jobs and leave magnets with my phone number everywhere.


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## eaglei (Sep 21, 2012)

I have always used wirsbo pex-a for three reasons , one it is more flexible two it is what my supply house carries and third i never had a leak in 20 years. Now they stock pex-c made by nibco . So i asked the guys why you would go from stocking pex-a to a pex-c , their answer was that the manufactuer (NIBCO) told them that pex-c is the best quality pex made . I only use pex for radiant heating mostly in slab installations so its important that i use the best quality . Also its not allowable for supply lines by code in NYC. I can't see a company like nibco manufacturing a pex-c that is not high quality !! The process for cross linking a pex-c is that its cross linked after extrusion with radiation , others are done chemically . Im not worried about making connections with fittings , just the quality of the tubing itself .


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## rjbphd (Feb 5, 2010)

Ya a plumber??? About an intro like the others did???


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## Mississippiplum (Sep 30, 2011)

rjbphd said:


> Ya a plumber??? About an intro like the others did???


He's a GC according to his profile

sent from the jobsite porta-potty


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## rjbphd (Feb 5, 2010)

Mississippiplum said:


> He's a GC according to his profile
> 
> sent from the jobsite porta-potty


Oh... but no intro??


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## Mississippiplum (Sep 30, 2011)

rjbphd said:


> Oh... but no intro??


He's got an intro

sent from the jobsite porta-potty


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## rjbphd (Feb 5, 2010)

Thanks.. will be looking for it


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## Protech (Sep 22, 2008)

eaglei said:


> I have always used wirsbo pex-a for three reasons , one it is more flexible two it is what my supply house carries and third i never had a leak in 20 years. Now they stock pex-c made by nibco . So i asked the guys why you would go from stocking pex-a to a pex-c , their answer was that the manufactuer (NIBCO) told them that pex-c is the best quality pex made . I only use pex for radiant heating mostly in slab installations so its important that i use the best quality . Also its not allowable for supply lines by code in NYC. I can't see a company like nibco manufacturing a pex-c that is not high quality !! The process for cross linking a pex-c is that its cross linked after extrusion with radiation , others are done chemically . Im not worried about making connections with fittings , just the quality of the tubing itself .


Seeing as how code limits the bend radius, why would it being "more flexible" have any benefit. (it's not actually more flexible)


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## eaglei (Sep 21, 2012)

Protech said:


> Seeing as how code limits the bend radius, why would it being "more flexible" have any benefit. (it's not actually more flexible)


 We work in some extremly cold weather and when 9 inch centers are called for it can mean weather we work or not . I've never used pex-c before so i dont know how flexible it is . I've used pex-b and find it to be less flexible than wirsbo . What do you find to be more flexible ?


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## Protech (Sep 22, 2008)

eaglei said:


> We work in some extremly cold weather and when 9 inch centers are called for it can mean weather we work or not . I've never used pex-c before so i dont know how flexible it is . I've used pex-b and find it to be less flexible than wirsbo . What do you find to be more flexible ?


Most pex b is more flexible than pex a. If space is tight, would the smaller fittings of pex b be a plus? In cold weather I would much rather do crimp joints than cold expansion joints. Wouldn't you agree?


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## eaglei (Sep 21, 2012)

Protech said:


> Most pex b is more flexible than pex a. If space is tight, would the smaller fittings of pex b be a plus? In cold weather I would much rather do crimp joints than cold expansion joints. Wouldn't you agree?


 Yes i agree with crimp joints , by flexible i mean installing pex for radiant heat under slab with 9 inch centers . Nothing to do with space being tight . My experiance with pex-a wirsbo is that it is the most flexible and expensive imo but is it the best quality ? .


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