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CPVC – Cold Water Only

splintergroupie | Posted in General Discussion on November 13, 2009 01:04am

I was surprised to find CPVC fittings labeled “COLD WATER ONLY”. I did some online research and the change seems to have taken a few others by surprise, too. It seems that in transitions from CPVC to metal, the varying coefficients of the different materials have caused leaks, in the male as well as the more-prone-to-leakage, female fittings.

The remedy are fittings that have pipe thread on one side and molded-in-place plastic slip fittings on the other.

I googled here for info and found nothing that addressed this, so thought i’d mention it. I’d already googled some inspection forums where the inspectors said they’d fail an installation using the all-plastic fittings for connection to metal valves, etc. on a hot water line.

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Replies

  1. frammer52 | Nov 13, 2009 05:24am | #1

    Haven't seen CPVC in years.  Didn't know they still sold that stuff!

    1. gfretwell | Nov 13, 2009 09:05am | #2

      I haven't seen a house plumbed with copper for years, so it must be a local thing. Everything is CPVC here.

      1. plumbbill | Nov 13, 2009 09:35am | #6

        I use a lot of copper, as most plastics do not meet the fire rating that my jobs require.

        My highrise condo's use copper & stainless mains & pex for the unit piping.

         

      2. frammer52 | Nov 13, 2009 03:11pm | #10

        Our local unions have a lot of control.  But saying that, most new houses are in pex.

      3. splintergroupie | Nov 13, 2009 06:15pm | #12

        I've replaced a fair amount of CPVC in MT with PEX after it had frozen and shattered, but i'm helping out a friend in MS now, replacing 50 y.o. galvanized that we found was nearly cemented shut. I still see CPVC for sale in MT, though i'm not sure why, as it's a recipe for disaster when it freezes, moreso than metal pipe. Frammer is in cold country, so perhaps it's outlawed in his area.I called the city here to get the code, plus double-checked with three of the larger plumbing outfits to find out it's used all the time in the South, where freezing isn't an issue. It seemed the correct solution to the problem, considering i can replumb this whole house for about 150 bucks in materials compared to 3X that for PEX.

    2. frenchy | Nov 13, 2009 09:19am | #3

      Yes they do and back in the 1970's I thought that CVPC was a cheap solution to plumbing and removed as much as I could while replacing it with copper.  A few decades later when I tore down my old house I had a chance to inspect the copper that I replaced and choose to  do my whole house in CVPC

       90% of the CVPC was in perfect shape and yet some of the copper was pretty badly etched on the inside.

        As a result I reused most of the CVPC  and continued using  it for all the new plumbing..   MY only concern is that from the meter to the shut off value is all copper and when that starts too leak  The city will have to come out and shut off the water out in the street to replace it..  Imagine what that will cost and how long it will take to get the city to do it!

      1. plumbbill | Nov 13, 2009 09:44am | #7

        Cpvc is getting out gunned by pex now days.

        Did you look into why the copper was being etched? Mid 70's had a huge batch of cheap imported chinacrap copper that would not meet the CDA's standards for use on a potable water line.

        Which shut off are you referring to?

        The one in or just in front of your house or the one that belongs to the water department located at the meter?

         

        1. McPlumb | Nov 13, 2009 11:02am | #8

          1" orange CPVC is used in sprinkler systems around here.

          I've always had good luck using the male plastic into female metal fitting setup.

           

          Highjack

          Ever drop a copper fitting and distort it?  Put your Aqua pex tool in it and gently expand it, works great.

          Highjack over.

          1. plumbbill | Nov 13, 2009 11:15am | #9

            Our highrise condo's use orange cpvc for the sprinkler as long as it's not through a 2hr rated wall.

            Thanks for the tip, generally if I drop a sweat fitting it's 2" or larger ;-)

             

            Edited 11/13/2009 3:17 am ET by plumbbill

          2. splintergroupie | Nov 13, 2009 06:33pm | #14

            <<good luck using the male plastic into female metal fitting setup>>Me, too, but it seems the standards have changed. Check out the Plastic Pipe and Fitting Association file i referenced for Plumbill. You can still do it on cold lines, but they found that thermocycling of different materials, over time, lessened the fit and leaks occurred between even male CPVC and female metal pipe thread. The new female CPVC fittings have neoprene washers in them and non-interference threads, so you can twist a shower arm into one just as if you're attaching a garden hose, using the washer to stop leaks. That part seems dodgy to me, but i'm just a DIY, so whadda i know? <G>

          3. McPlumb | Nov 14, 2009 03:49pm | #19

            Check out Sharkbite fittings, they solve a lot of problems.

            The Sharkbite distributor was at the local plumbing supply house recently with his sample case.

            They now offer 120+ different fittings, it was a pretty impressive assortment. They have put alot of effort into introducing new products.

            The distributor said Sharkbite fittings are approved for burial, this may of course very with location.

            He also gave me a free hat, so of course I'm sold on Sharkbite. :^)

          4. splintergroupie | Nov 14, 2009 09:04pm | #25

            Sharkbites are dandy, and i've also used the other brand made of some sort of white plastic, in a pinch. But the cost! I'm going out today for supplies to replace a failing gas H2O heater that was hard-plumbed with copper, and Sharkbites will figure into the mix so that i don't have to deal with soldering in a dusty laundry room. At $5 a pop, they add up too quickly for a whole-house job.MY pref is PEX, but i'm not getting my way with my friend's house and wallet. <G>

      2. frammer52 | Nov 13, 2009 03:13pm | #11

        Funny, our city doesn't fix water lines past the curb box.

        1. User avater
          Matt | Nov 14, 2009 02:16pm | #18

          I think he means from the water meter to the cut-off in the street.  Here, they tap into the mains with something called a corporation and technically I guess it is a cutoff as it has a bolt that can be used to cut off the water flow.  Still, these copper lines under the street are heavy copper.  See attached pics.  FYI, the mains in the pics are ductile iron, the 'corporation' is bronze, and then to the copper that feeds the meter.

          Personally I'd be more concerned about the economy getting so bad that hard working people who have fallen to the level of thieves might dig up the copper and steal it. ;-)

          Tip: There are only a few people's posts who generally I don't read since I need to make good use of my time.

          1. frammer52 | Nov 14, 2009 04:34pm | #20

            Personally I'd be more concerned about the economy getting so bad that hard working people who have fallen to the level of thieves might dig up the copper and steal it. ;-)>>>>>>>>>>>>>>>>>>>>>>>>>>

             

            Yoo much work.  That is like the neighborhood I live in.  You can leave extension ladders out and nobody steals them, leave a handtool out and it lasts about 5 minutes!

          2. User avater
            Matt | Nov 14, 2009 04:47pm | #21

            I was joking about the copper being stolen. :-) 

            I've built several houses in the inner city.  Never a material theft.  I always say "they won't steal materials because that would mean that they were getting ready to do some work". :-)  A sub did have a 40' extention ladder stolen though.  It was chained to a tree.  They cut the chain.  Go figure...  OTOH, pawn shops do sell ladders...

          3. frammer52 | Nov 14, 2009 04:56pm | #22

            OTOH, pawn shops do sell ladders>>>>>>>>>>>>>

             

            Not around here thank God!

          4. User avater
            Matt | Nov 14, 2009 05:33pm | #23

            I've seen ladders out front while driving by.  Far as I know pawn shops mostly sell stolen stuff and stuff from people who are really down on their luck.   I don't patronize the places myself.

            "I'll give you $15 for that $120 circ saw (thereby taking any hope what so ever that you can make a living) and then put it up for sale in my shop for $100"  Even though it is 1/2 worn out....  "Course, you gotta wait until it sells to get your $15."

    3. plumbbill | Nov 13, 2009 09:33am | #5

      We use large bore CPVC for spas & pools when the pipes are ran in or through an air  plenum.

       

  2. plumbbill | Nov 13, 2009 09:31am | #4

    If you're going to transition from metal to plastic with a threaded adapter make sure that the plastic has the male threads & the metal has the female.

     

    1. splintergroupie | Nov 13, 2009 06:25pm | #13

      <<If you're going to transition from metal to plastic with a threaded adapter make sure that the plastic has the male threads & the metal has the female.>>Yeah, i knew about that, and merrily plumbed a male fitting to the tub/shower diverter when my "layman" HO pointed out the "cold water only" raised letter in itsy-bitsy lettering on the male fitting. Here's a discussion i found where even some inspectors were as surprised as i was:
      http://www.inspectionnews.net/home_inspection/plumbing-system-home-inspection-commercial-inspection/7943-cpvc-fitting-labeled-cold-water-only.htmlAnd here's the manufacturer's file on it, if you click on the link near the top of the page for the installation handbook and then go to page 5 and look at the section on transition fittings:
      http://www.ppfahome.org/cpvc/index.html(It's a pdf file and i can't copy/paste the relevant section, sorry.)

      1. User avater
        BillHartmann | Nov 13, 2009 07:18pm | #15

        You can copy and paste most PDF files. However, they can put a tag in them that prevents C&P, but it is not common.I used the plain, free, Adobe reader on this."TRANSITION JOINTS & FITTINGS
        Special transition fittings or joints are used
        whenever CPVC piping is connected to a
        metal valve, fitting, or other appurtenance
        such as a filter, or to parts made of another
        plastic. These special transition fittings can
        have many forms (photo I). One common
        form is the true union with a metal end and a
        CPVC end held together with a plastic or
        metal gland nut and having an elastomeric
        seal between them. Other forms are the
        flanged joint, the grooved joint, insert molded
        metal in CPVC fittings, patented push-on type
        fittings, and finally the CPVC female threaded
        adapter with an elastomeric seal at the bottom
        of the thread. The latter fittings are designed so
        that they have no thread interference and rely
        entirely on the elastomeric seal for water
        tightness. They require only minimal torque to
        attain an adequate seal.
        Standard compression fittings that utilize
        brass or plastic ferrules can be used to assemble
        CPVC (photo J). However, Teflon¯ tape
        should be applied over the brass ferrule to
        compensate for the dissimilar thermal expansion
        rates of the brass and CPVC that could
        possibly otherwise result in a drip leak. Care
        should be taken not to over-torque the compression
        connection.
        Metal fittings with CPVC socket inserts are
        also available. The tubing is cemented directly
        into the socket in the same way as an all-CPVC
        fitting.
        The standard practice is to thread a male
        thread adapter into the female threaded part,
        such as a valve or stop, and then solvent
        cement to the CPVC pipe. However, when using
        the male thread adapter, there are two limitations
        that the installer must consider when
        deciding where and how to use it. First, the
        male thread adapter may develop a drip leak if
        the joint is subjected to too broad a temperature
        range. And second, some thread sealants
        intended to minimize leak problems may
        chemically attack the CPVC and cause stress
        cracking of the adapter (see Thread Sealants
        section). The preferred method of transitioning
        between metal and CPVC plumbing components
        is to use an insert molded metal-in-CPVC
        fitting or true union with a metal and a CPVC
        end.".
        William the Geezer, the sequel to Billy the Kid - Shoe

        1. bearmon | Nov 14, 2009 11:28am | #16

          CPVC does not meet code here.  Funny, you can buy it here, but you are not supposed to use it.Bear

          1. User avater
            Matt | Nov 14, 2009 01:47pm | #17

            Maybe it can be used for repairs but not installs?

        2. splintergroupie | Nov 14, 2009 08:58pm | #24

          Thsnks for doing that, Bill, and i'm glad to see your recent replumbing didn't slow you down on the boards. ;^)I've c/p'd stuff from a pdf on my windoze machine, but i've never cracked the code on doing it on the Mac that i'm using these days. Thanks very much for posting the relevant passage.

          1. User avater
            BillHartmann | Nov 15, 2009 05:17pm | #26

            You might find this "useful". It is a news story that I posted in the tavern.http://forums.taunton.com/tp-breaktime/messages?msg=126554.2.
            William the Geezer, the sequel to Billy the Kid - Shoe

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