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Pex A vs Pex B

I better go run and hide. I'm laughing so hard I can not see the keyboard. PexB crosslinked on site. HAHAHAHAHA.

To All. I've been around the block a lot. I looked for Elvis back in the 80's with Dan. I gave up rubber for crossed link mulitcore rubber. I trades A for C and now for B. I think DVW said it best, PEX is PEX. I can argue all sides of the ABC issue. They are all GREAT, they all last beyond any of our expectations.

I'm going to chuckle on this one for a looooong time.

(said now in a whisper like I was passing you drugs) Quick, Tim, before PPI can test our pipes, run some water through it so it can crosslink. hey, maybe it will clear out some of the FREE RADICALS too. HAHAHAHAHAHAHAHAHA.

wheels

Comments

  • Dorsey Davis
    Dorsey Davis Member Posts: 14
    Pex A vs Pex B

    So what are some of the differences between pex A and pex B? I know that the A is carbon to carbon bonds and the B is an oxygen-silicon-oxygen bridge, therefore A is a bit stronger of a bond. The question is how does it play out in the field? Are there studies yet of the longevity of either of them? And the big question from clients is how much longer does pex last, in general than copper? Thanks oh wise ones....
  • singh
    singh Member Posts: 866


    Pex A or Pex C are the only types I've seen in the field.
    I don't know who sells or manufactures pex B

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  • Dorsey Davis
    Dorsey Davis Member Posts: 14
    Pex A vs Pex B

    an online company blueridgecompany.com sells it. It has the advantage of being usable for potable and heating. The B is slightly less flexible than the A
  • Paul Rohrs_4
    Paul Rohrs_4 Member Posts: 466
    Pex

    Viega manufactures a PEX C, but they have recently acquired Vanguard with manufactures a PEX B product.

    Both PEX B and C are post extrusion process', meaning that the cross-linking is done after it is extruded. Pex A's cross-linking is achieved during the extrusion.

    Ford vs. Chevy

    Fintube vs. CI

    Condensing boiler brand "X" vs. Condensing boiler Brand "Y"

    Good vs. Evil

    Take your pick, they all have their merits. Manufacturers fall all over themselves why they are more "top-shelf" than the rest.



    Regards,

    PR

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  • Jim_65
    Jim_65 Member Posts: 184
    Watts Radiant

    is another Pex B.
  • Ich Wundermich
    Ich Wundermich Member Posts: 17
    good vs evil...

    Take your pick, they all have their merits??????
  • Dorsey Davis
    Dorsey Davis Member Posts: 14


    I like the good vs evil line meaning no difference...very zen.
    When you look on Wikipedia it says that pex lasts 50-200 yrs. That's quite a range. So what I'm seeing here is that the only difference is flexibility.
  • JimL
    JimL Member Posts: 21


    PEXa and PEXb are both manufactured using a chemically "induced" crosslinking processes. PEXa is crosslinked in the manufacturing process with peroxide and PEXb uses Silane. The main difference b/w the 2 is that the introduction of the Silane does not in itself crosslink the PE. Only after water is introduced and allowed to react with the Silane does the PE actually begin to crosslink. It's pretty much crosslinked on-site when the system is filled. PEXc uses an electronic process of crosslinking during extrusion. Arguments are made that this is the most effective cross-link process due to it's controlled nature. Second place I suppose would be the PEXb and in last place is PEXa due the nature by which the Silane interacts to crosslink the PE. Vangaurd is in fact PEXb, however, they use a method by which the Silane crosslink process is controlled and initiated by the introduction of steam during the manufacturing process which yeilds much better product in the end than other Silane PEXb processes.
    Hey, at least that's what I thought I heard at Viega training last week!
    onemoosehorn
  • Tim Doran
    Tim Doran Member Posts: 208
    Had to read this twice

    "Pex-b is pretty much cross linked on-site when the system is filled"????????? Then how does it pass any sort of quality control or third party testing. How do they know what they are selling until you fill the system? I seriously hope that someone is not teaching this. Pex-b is put into a sort of sauna to activate the cross link and it does not magically cross link on-site. How could that process possibly be controlled? Vangaurd is not the only company to properly manufacture pex-b

    "And in last place is PEXa due the nature by which the Silane interacts to crosslink the PE." There is no silane in Pex-a.

    I am not going to get into the pex vs. pex war again but I did want to clarify a few of your misconceptions. Just a few thoughts though. Pex-a has been in use the longest and has the most lineal feet of tubing installed worldwide, without any significant incidents that I am aware of.

    Tim D.
  • JimL
    JimL Member Posts: 21


    Tim,
    Obviously, it was a bias opion to promote their PEXc irradiation process being superior to either the A or B. I'm sure the A and B manufactures would beg to differ. You are correct, there is no silane in PEXa. My bad. It was my disPEXia.
    Contrary to your belief however, PEXb can be processed without the sauna treatment and x-linked after the fact.(Vanguard not being one of them)Silane x-linking is accomplished in two distinct methods as described in the specialchem website.

    http://www.specialchem4polymers.com/tc/silane-crosslinking-agents/index.aspx?id=pipes

    per Specialchem...."The use of silane technology provide flexible pipe facilitating installation and allowing complex shaping. When installed, pipe can be cured by the circulating hot water."

    I'm not advocating the use of A,B or C as I have used all successfully over the last 10 years. Personally, I use known brands as opposed to trying to save a few pennies with the generic varieties.

  • Scott Gregg
    Scott Gregg Member Posts: 187
    try it!

    Get a 1' chunk of Rehau or Wirsbo.

    Get a 4' chunk of VAngaurd, watts, ect.

    Bend and kink unitl you break each!

    See what happens
  • just did

    Piece of Wirso, Watts and Roth (AB&C)

    Roth fell in half first. Watts second. Wirsbo never broke completely. None were usable after the first kink

    Not too much difference in b&c (like there was many years ago)

    But what does all this prove?
  • Scott Gregg
    Scott Gregg Member Posts: 187
    Kinks repariable with PEXa in most cases

    I you take a heat gun to a kinked piece of PEXa, it will return to its former state without harm. It you kink it until you get a crack of course it is too far gone, however any kink you may get in the field is easily repairable and you don't need to cut in a coupling.

    What it proves is the strength of the tubing, its flexibility and its ability to be repaired without adding joints in the filed if you do kink it trying to get a tight radius bend.
  • Tim Doran
    Tim Doran Member Posts: 208
    Hey Wheels

    > I better go run and hide. I'm laughing so hard I

    > can not see the keyboard. PexB crosslinked on

    > site. HAHAHAHAHA.

    >

    > To All. I've been around the

    > block a lot. I looked for Elvis back in the 80's

    > with Dan. I gave up rubber for crossed link

    > mulitcore rubber. I trades A for C and now for B.

    > I think DVW said it best, PEX is PEX. I can argue

    > all sides of the ABC issue. They are all GREAT,

    > they all last beyond any of our

    > expectations.

    >

    > I'm going to chuckle on this one

    > for a looooong time.

    >

    > (said now in a whisper

    > like I was passing you drugs) Quick, Tim, before

    > PPI can test our pipes, run some water through it

    > so it can crosslink. hey, maybe it will clear out

    > some of the FREE RADICALS too.

    > HAHAHAHAHAHAHAHAHA.

    >

    > wheels



  • Tim Doran
    Tim Doran Member Posts: 208
    Hey Wheels

    Long time no see! Yep, on-site cured pex-b is one for the books. I hope any company that is doing this doesn't claim any level of quality or any compliance to astm standards. It would be impossible to test and quantify.

    Tim D.
  • repairable

    Scott,

    Please, read all the fine print in the manuals before jusmping to conclusions. A lot of trainers will vernally pass along a lot of information that can be misleading.

    In physical tests and studies done by third parties ALL three types are repairable if kinked by using heat. ALL three can be heated to 315F and the kink will be repaired.

    All three types will be damaged if heated over 340F!!!!

    All three will be damged if left out in the sun, some A's much faster then come B's & C's.

    All three have the same rated pressure, the same rated temperature, the same ASTM standard to live up to, the same PPI standard to live up to, the same UPC standards.

    All three will leak if you put a nail through them.

    Some are MUCH smoother on the inside then others.

    Some manufacturing methods differ greatly from each other, even within the same type.

    What to look for then? A reputable manufacture with enough assets to cover your butt if something does happen.

    Just my 2 cents for the moment.

    Steve
  • grarya01
    grarya01 Member Posts: 1
    Silane (pex-b) vs. Engel (pex-a)

    According to Zurn, unlike the Peroxide/Engel (PEX-A) and Radiation/E-beam methods, Silane produced pipes will continue to cross-link to completion, if necessary, even after the extrusion process is completed. Although both methods adhere to the strict ASTM standards, Zurn tests found that the tensile yield strength and quick burst testing results show that the Silane method is considerably stonger than Engel produced pipe.

    A carbon-carbon bond has a slighty higher bond energy than a carbon-silane bond, but because there are many factors contributing to the strength of PEX tubing other than molecular bond strength, we must consider the fact that the Silane method has produced superior results in regards to tensile yield strength and quick burst strength. Both methods create bond energies over 2.5 times stronger than Copper (cu-cu).

    Conclusion:
    The carbon-carbon bonds of PEX-A are only slightly higher in strength than that of the carbon-silane bonds of PEX-B (as stated earlier, both types are over 2.5 times stronger than copper-copper bonds). This means both types of pipe will hold up considerably longer over time than copper pipe. Proponents of PEX-A will tell you that because the carbon-carbon bond strength is slightly higher, this means it will last longer than PEX-B. However, all PEX tubing that is ASTM rated will have a long life. Given this information, it seems more important to focus on the qualities of the pipe in reaction to the environmental stresses it will meet along its life. Due to the fact that Zurn tests have show PEX-B (silane method) has a higher tensile yield strength and quick burst strength than PEX-A, in some people's opinion makes it a superior pipe, and it should be further concluded that if it reacts better to it’s environmental stresses over the short term, that it will hold up better over the long term, despite the slightly lower bond strength.
  • Scott Gregg
    Scott Gregg Member Posts: 187
    There is a but there...

    THe PEXb ans c products are more likely to sustain structural damage then PEXa before being repaired. For instance, if it is very cold and you get a kink with a PEXb, you may crack it and not notice it...until test day. PEXa is much more forgiving.

    Take two people and "race to break" any PEXa against any PEXb or c and as soon as the fellow with the b breaks the joint, take the PEXa (With a nasty kink) form the other fellow and repair it. It's simply and expamle of the flexibility and streanth of the PEXa.

    Ask anyone who hgas pulled both ans they will attest to the better flex of PEXa also.

    The differences are not huge but they are there and better is better.
  • I'll choose just to disagree

    Scott,

    After 20+ years of using and selling all three, I'll put 50 blindfolded contrcators in a room and have them install all three.. and I bet no one would really give a hoot.

    Comes down to customer support. ANd that boils down to three words, "Dedication, Integrety and Confidence."

    Apparently you really like Uponor. Good people, nice product, great support. Don't change.

    Enjoy,

    Steve
  • Gregory Pex
    Gregory Pex Member Posts: 9
    Jim what type of pex...

    would Fonzy (From Happy Day's) install...
    thats right! AAAAAAAA Pex. -Greg
  • leo g_13
    leo g_13 Member Posts: 435
    a bit more \"sales\" talk

    had a vanguard rep tell me once, that though the silane bonds were not as strong as the carboza bonds, in fact their tubing was much superior, because they had up to 80
    % cross linking throughout their product, where as the "other" guys was just a mere 50%.

    I smiled, nodded my head and said, "well isn't that special!".

    As others have noted, I also have used all 3 types, and ALWAYS stuck to a reputible manufacturer, and so far, touch wood, have had no real problems!

    Leo G

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  • Tim Doran
    Tim Doran Member Posts: 208
    Cross Linking

    As I understand it there is a lot more to this than just the cross linking. I have been told by several chemical engineers that the cross link is there more to prevent "creep" than to provide strength and that much of the strenght of the tube has to do with the molecular weight of the raw material and any sort of additive packages. All plastics "creep" which is to say that they flow at a molecular level even after becomming what we consider to be solidified. This flow of molecules can lead to uniformity issues in the product. Other things like metals and glass also creep over time or based on environmental conditions. The reason that differnt methods of making pex have different amounts of cross linking is that they have different molecular weights and that the molecules are of different sizes. The cross link has to form a net to catch these creeping molecules so the amount of cross link sets up the size of the mesh according to the size of the molecules which is based on the material used in a particular method and has little to do with actual strenght.

    Tim D.
  • Jim_65
    Jim_65 Member Posts: 184
    Hilarious

    That made me laugh out loud!

    When I was at tekmar everything was followed with AAAAAAA...Eh? Actually made some great friends on that trip. Good guys!
  • heatboy
    heatboy Member Posts: 1,468
    Well...............

    ....I have used almost all of them at one time or another, but Uponor (pex A) is my favorite.

    hb

    www.climatecadvanced.com
    heatboy



    The Radiant Whisperer





    "The laws of physics will outweigh the laws of ecomomics every time."
This discussion has been closed.