PEX still good if you heat it?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by petrie, Mar 20, 2014.

  1. petrie

    petrie New Member

    Messages:
    56
    Location:
    Wisconsin
    I did a 1/2 bath in my basement a few years ago. Came off the copper with PEX. It's the red and blue nibco stuff that my local big box sells. I have the watts cinch clamps holding it together. Anyway I was planning on adding a shower and I would need to remove some elbows and add some tees. I can cut the clamps and heat the pipe to remove them...heat takes out clamp groove. Can I just stick a new fitting cinch it up and be done. Or, does heating the pex damage it?
    Last edited by a moderator: Mar 21, 2014
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,825
    Location:
    Cave Creek, Arizona
    You will melt the PEX before the cinch releases. Either cut the clamp off or cut the tubing at the fitting and shorten the tubing.
  3. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,139
    Location:
    New England
    If you cut the clamps, and can do it without damaging the PEX, you shouldn't need heat to remove the fitting. It should pull out. But, if you are careful with a heat gun, and don't melt things, you can relax the PEX, and if you couldn't get the fitting out, you then should. But, by far, the easiest thing to do is to cut it off and put in new. It can get messy if things are tight and that results in not enough slack to make up the new connection.

    FWIW, on type A PEX, a heat gun can be used to relax the pex if you created a kink, and type A is the only one that allows that...a kink in any of the other types (B and C), require you to cut out the kink and install a fitting...it's a function of the amount of cross-linking (type A has the most), and the ability to retain strength. I do not know if they consider a crimped end in the same category...your best bet is to read the installation instructions carefully, or call the manufacturer directly on what is allowed with their tubing.
    Last edited by a moderator: Mar 21, 2014
  4. petrie

    petrie New Member

    Messages:
    56
    Location:
    Wisconsin
    I get what you guys are saying for the price of this cheap type C PEX I might as well keep the fitting, but just cut a new piece of pipe. I kinked a piece of the pex and then heated it with a heat gun. It does comback most of the way from the kink and I can heat away the mark from the clamp.

    I wish my big box store sold some class A or B PEX. I might just buy a 100 ft roll of Viega or Rifeng online and ditch the nibco stuff. I can easily replace the pipe I have I might just replace it all with a better grade of PEX. Although I'd still want to stick with Watts cinch clamps... Not really into plumbing enough to justify spending much on installation tools.
    Last edited by a moderator: Mar 21, 2014
  5. SHR

    SHR Member

    Messages:
    111
    Location:
    Minnesota
    There is some mis-information flowing here. The three types of PEX are differentiated by what process was used to manufacture the tubing, not quality! Type C PEX is the same quality as A & B. I wish they would have used a designation system that did not resemble grading. Yes, type A is the only one which states in it's specs that you can heat kinks out, but the other grades are great quality too. I personally use the Nibco and other brands of tubing regularly and have never had a problem with any of them. Do not "ditch" the Nibco stuff, you have good quality tubing. I would use any of the name brand PEX tubing, including Nibco, without reservation.

    Now your Watts cinch clamps. I use copper crimp rings but cinch clamps have been used on all types of tubing with great success for decades. Unfortunately, lately plumbers have been having issues with Watts brand cinch clamps breaking during installation. I do not know if something changed with their manufacture or is it is a quirk. Time will tell if there are issues down the road with this brand of clamps.

    To re-do sections of tubing, cut the cinch rings and the tubing over the fittings off, and re-use the fittings. Do not use the same bit of tubing on a fitting more than once. That would be difficult anyway because the tubing rarely comes off the barb end easily and in one piece.

    It seems you are on the right track, just a little mis-informed and frustrated. Do not worry, PEX is forgiving, it will turn out good. Good luck with your project.
  6. petrie

    petrie New Member

    Messages:
    56
    Location:
    Wisconsin
    Good to hear a vote of confidence in the Nibco pex. I read a long thread about failures in Nibco pex on this forum. It seemed like the problems were concentrated in a specific geographic area over a certain time frame. "Bad Batch" maybe. I'm sure HD has sold a million miles of this stuff as they are the only big box diy in the area.

    As far as the cinch clamps, I have to assume they aren't quite as good as the copper crimps. Otherwise who would buy those big bulky tools that are much more expensive.


    My cousin payed a plumber and had all the copper in his house replaced with wisboro 3 years ago. all the fittings are plastic and done with an electric spreading tool. Price was very reasonable. He didn't know good pex from bad...just sort of lucked out that guy was wisboro installer.
  7. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,139
    Location:
    New England
    If you think I inferred a difference in quality between the -A, -B, and -C manufacturing methods of making pex, I'm sorry, that is not what I intended. They all meet the requirements for use in a home. Type -A was the first, and as process technology advanced, other, less expensive methods were developed, resulting in -B and -C. It just happens that -A, the first method developed, remains the one with the most complete, longest chain polymer which makes it the version with the smallest bend ratios and the only one that can be restored if it gets kinked. It has the best memory, and is generally installed with the use of an expansion system, but cinch rings can be used on it.

    The biggest thing with ANY pex, and most materials, is good ingredients and proper quality control during manufacture. Errors can happen with any of them, regardless of the type. Some have been doing it longer than others, and, I think, the only one that has a vertical manufacturing process (where they control all of the processes and ingredients) is Uphonor. Doesn't mean others are bad, but if you have an issue with theirs, someone within the company messed up, not a supplier.
  8. SHR

    SHR Member

    Messages:
    111
    Location:
    Minnesota
    I love Uponer (formerly Wirsbo) too. Their US headquarters and manufacturing are near my home and I love to support companies where my neighbors work when possible. I do not recommend the Uponer system to DIYers only because the minimum cost of an expander tool worth using is around $400 and the components are only sold locally through wholesale supply shops. Thank you jadnashua for clarifying your PEX info. I agree with your latest post. I have to reiterate that I regularly use a few different brands of PEX and am always happy with the end result.
  9. craigpump

    craigpump Member

    Messages:
    971
    Location:
    ct
    Used manual expanders can be had for about $100.00
  10. SHR

    SHR Member

    Messages:
    111
    Location:
    Minnesota
    If you have 3 hands or a helper. They stink to use...I hate them and will not use them. I know, whiny.
    Last edited: Mar 22, 2014
  11. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,139
    Location:
    New England
    For a DIY'er, only installing a few things on a remodel, the manual expander can work. You need to have really strong hands and good endurance to use one of those all day, though...the powered ones are MUCH less work!
  12. petrie

    petrie New Member

    Messages:
    56
    Location:
    Wisconsin
    So, my take away is that C grade pex is just fine, but don't expect it to be as bendable and kink proof as Grade A or Grade B to a lesser extent. Is it true that Grade C pex is more like plastic pipe than pex though? I read that the manufactureing process for Grade C pex doesn't give it as many bonds...whatever that means.
  13. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,139
    Location:
    New England
    Your mistake is calling them 'grades', they are not grades, they are types of manufacturing. Type -C is the newest method, that does not make it the best or worst, just the newest method to make it. The thing that gives pex its flexibility is how long the polymer chain is...I do not know the variations in the methods, but type -A, as far as my research goes, says it has the longest chains which is why it has the smallest bend radius and a kink can be repaired with heat. The others require any kink to be cut out, and a fitting be installed in its place.
  14. petrie

    petrie New Member

    Messages:
    56
    Location:
    Wisconsin
    http://www.pexsupply.com/Rifeng-PEX-Plumbing-Tubing-11916000

    Not saying they are right, but you watch this video and they consistently refer to the "grade" of pex and say that A is the highest quality and that B doesn't bend as much, but is still high quality. They don't even mention C, which by omission leads a person to believe there must be something wrong with it.
  15. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,139
    Location:
    New England
    It depends on the characteristics you want in the tubing...as I said, -A, the original method, is often the most expensive because of its superior characteristics and longer, more expensive process required to make it, but if the bendability and kink repairability aren't important to you, the others work just as well. Everyone is always looking for a less expensive method to make things, and over the years (it's been over 30-years), they've developed two additional methods to make pex, and in succession, they were labeled -B, and lastly, -C. If someone comes up with a new method, it will likely be called -D, and as material science improves, it might be 'better' than -A...won't know until it happens.

    Anyone using those manufacturing methods as an indication of the quality of the tubing is just wrong, they just end up with variations in the length and quality of the long-chain polymerization, and that affects the other properties. Some people run pex like copper, and use lots of fittings...in that case, flexibility is almost irrelevant.
  16. SHR

    SHR Member

    Messages:
    111
    Location:
    Minnesota
    Hallelujah, Amen! I know it is confusing because the Europeans who first started using PEX those 30+ years ago used designations which are often confused with quality. To everyone - do not overthink this. There is tons of mis-information on this subject being peddled as fact out there. The A,B,Cs of PEX are just manufacturing method designations. Anyone who claims otherwise is either mis-informed or a salesperson. The only good reason to use type-A over any of the others is if you wish to use expansion fittings, then you have to use type-A. (Unless you want to count that it is made by Uponer in the vicinity of where I live, instead of somewhere else in the USA.) That is a characteristic difference, not a quality difference. People: do not sweat the type designations.
  17. petrie

    petrie New Member

    Messages:
    56
    Location:
    Wisconsin
    Really glad you guys are clarifiying this. Nice to know that the product that is readily available in my area is a good product. But I shouldn't try and heat out kinks or make too sharp of bends.
  18. SHR

    SHR Member

    Messages:
    111
    Location:
    Minnesota
    Yes. This whole thread boils down to that short statement. Good luck!
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