Expansion tanks and relief valve piping

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    • #273169
      Avatar photoMasterPlumbers

        I saw my first expansion tank on a waterheater, then noticed that the relief valve pipe was plastic, not copper. I was always told that you had to use copper piping, plastic could melt during venting. Does having the expansion tank change the peramiters on the discharge valve and pipe?

      • #287018
        Avatar photoSylvanLMP

          WOW who gave you this erroneous information? There are some TECHs out there that HAVE NO IDEA what kind of crap they are spewing.

          How could someone even say such a thing? All I know I would be very careful who I took plumbing advice from. For example

          PVDF can handle high temperatures up to 280 Deg. F (137 Deg. C) and CPVC and PP can handle temperatures up to 210 Deg F (98 Deg. C).

          Now what scares me is the no brain installers of relief valve piping who never bothered to read the ASME section IV or the National Board of boilers Inspectors (NBBI)

          I think I would rather brush up an INSULATING piece of plastic then leaving my skin attached to a nice piece of shinny copper tubing with 210 degrees passing through

          Most of the WANNA be “plumbers” also never bother to pipe the relief valve properly and only a hand full of professionals bother to cut the relief valve piping on a 45 degree angle to prevent some brain dead tech placing a cap or reducer on the plain end of this piping.

          Next time anyone gives you “plumbing” advice ask them how long they went to apprenticeship training? Anything less than 10,000 hours including 720 class room (codes & theory) run like hell from them as they have NO IDEA what a code book is.

          Ask to see their journeyman’s license (mechanic) This is all 2nd year basic apprentice training. Have fun and be careful out there the techs are lurking to get you it appears.

          the expansion tank is just that. As water gets hot it expands and like a hydronics heating system you need some place for the expansion to go SAFELY. Now before anyone and everyone started dabbling in plumbing and throwing check valves every place. The expanded water would travel back towards the city main Path of least resistance.

          Water main average pressure UNDER 150 PSI correct? Operating Limit of T&P 150 PSI so the excessive pressure would flow back into the system HARMLESSLY.

          Now comes a 12 week wonder heating and drain cleaning and plumbing expert and they throw a check valve in to prevent this natural condition and now cause a dangerous condition to develop
          (All the morons had to do was put in a 27″ heat sink made up of piping and fittings) But instead now folks have to depend on a rubber bladder to protect them from a dangerous pressure build up. 2 mechanical devices to worry about failing instead of one, now thats progress. Hey think about all the jobs that are now created by having folks buying these expansion devices God Bless HUH?

          [Edited by SylvanLMP on 05 July 2000]

        • #287019
          Avatar photoArt_xyz

            Sylvan, as a Licensed Master Plumber, you don,t really mean what you said about backpreasure/backflow DO YOU?

          • #287020
            Avatar photoSylvanLMP

              Sylvan, as a Licensed Master Plumber, you don,t really mean what you said about backpreasure/backflow DO YOU?

              Yes, Art I do as I stated “heat sink” would allow some “back flow” BUT not cause any health risk as We are talking DOMESTIC H/W not boiler water.
              The main OBJECTIVE is to protect the tank from rupturing READ ASME Section IV pleaseeeeeeee

              what would YOU consider more important
              A- allowing some H/W to go harmlessly into the C/W supply no more than 27″ HEAT SINK OR

              B- Put in an expansion tank that is prone to failure and possibly having it ALSO act as a NON Fire pressure vessel JETTING out of control once the rubber bladder gives up the ghost and THEN having the HIGH temperature HIGH pressure water FLASH INTO steam all because YOU felt the 27″ heat sink wasn’t good enough as this system is Mother nature at its best as it is NON mechanical. Hot Water Molecules my good man will not go down MORE than 27″ BUT to be safe and remember you have my permission to pipe it 30″

              One more point the U of the heat sink will take up for expansion and contraction. WE ARE TALKING POTABLE water NOT questionable Quality OK? Have a great one

            • #287021
              Avatar photoArt_xyz


                A person has a two story house and a home business (photo developing or another business or hobby where he needs to mix up some chemicals in the sink). This person built a really nice developing room upstairs (althouth it could have even been on the first floor or in the basement). The only problem is that he left the rubber hose which is attached to the faucet in the solution. NOW PAY CLOSE ATTENTION
                He turns on both the hot and cold water (of course being as he is a New Yorker in good standing he of course has a heat sink at his water heater) but for some reason instead of adding water to his solution, all the chemicals are sucked out of the sink, down and out of the house thru the COLD water piping (they just had a broken main down the street).
                Now my question to you is; How would you like to be his downstream neighbor getting your first glass of water after the main is fixed?
                I personally would prefer to be the neighbor of the guy with a double check at the water meter yolk.
                PS I know NY has some of the best drinking water, but if Plumbers don’t protect the water system who’s job is it? And yes I know that he should have had a vacum breaker on his faucet but he didn’t know any better.
                So like I said: You don’t really mean what you said about backpreasure/backsyphonage DO YOU?

              • #287022
                Avatar photoSylvanLMP

                  Art suppose a BULL had Square BUTT we could get bricks HUH?

                  First off the REASON NYC has the best water is we have the BEST codes and plumbers who follow codes. We are not country bumpkins when it comes to TRAINING

                  Art ANYONE can cause a Cross connection ANY PLACE BUT We in NYC have laws dealing with CRIMINALS who would do commercial work in a non commercial building

                  For example your talking Chemical waste disposal for a photo lab so we would use Duriron and an acid crock for neutralization as the Department of Environmental Protection frowns upon dumping hazards waste down the public sewers INCLUDING photo developing solutions. AND this would be picked up in a very shot time as WE do monitor sewerage disposal.

                  Now ONLY a NON NYC “plumber” would install a rubber hose on ANY faucet without a BUILT IN VB on the Faucet.

                  Hey Art pick up a Chicago Faucet catalog and SEE slop sink (service) faucets OR look at Brass craft lab faucets DUH. BUILT IN VB

                  If he has a photo SINK then he would have a faucet correct? most of the LAB faucets do have BF protection built in.

                  Since your “supposing” NOW using this same country Bumpkin mentality like your describing this same photo guy was building an ATOM Bomb in his basement THEN
                  I could see your point about ILLEGAL hook ups as radiation would cause poor tasting water. HUH? How many hose bibs have you installed lacking a VB?

                  In all reality I totally AGREE Art we SHOULD have a back flow preventer at all house mains therefore we can CREATE a better chance of more explosions in homes with a hot water tank as we will guarantee no place for the normal expansion of water to go EXCEPT place an undo burden on the piping system.

                  Remember a rubber bladder expansion tank does FAIL.

                  Most installers of Diaphragm tanks do not bother to take into consideration that they are mixing ferrous and non ferrous metals ON A POTABLE system.

                  HEY Art this is CONTRARY to code unless you of course use a dielectric fitting
                  (YOU DO KNOW WHAT THAT IS HUH ART? DUH)

                  What happens when the inet to this expansion tank gets blocked with RUST HUH ART please tell me WHERE will the HIGH pressure get relieved?

                  Art PLEASE, PLEASE, PLEASE read the ASME and National Board Of Boiler Inspectors books. Reading the NFPA may help you understand a little also about some of the dangers associated with Pressures allowed to go unchecked.

                  Have you bothered to READ the ASSE recient publications RE high pressure in water systems? Art stick with your one and two family homes THIS way you cant kill or main too many folks at one time.

                  Duh Art did you ever bother to read the H/W relief valve rated at 150 PSI and the piping WHEN NEW is rated at 125 PSI but hey you know what’s best.

                  If it makes sense to risk EVERY HOME cause 1 MAY create a cross connection THEN go for it.

                  By the way Art for you information A chemical processing tank for Photo chemicals DOES required Mixed water to prevent hot or very cold water from destroying the negatives.

                  Now MOST if not every manufacturer of this equipment also sells this supplying faucet with not only a thermometer BUT a built in Vacuum breaker as the water supply to these developing tanks is BELOW the “flood level rim”

                  But hey this your STORY so why confuse you with facts.
                  Have a GREAT week end and please keep away from REAL plumbing as you may hurt yourself. Stick with the BASIC’s and forget theroy and codes that only will give you a head ache.

                  [Edited by SylvanLMP on 07 July 2000]

                • #287023
                  Avatar photoArt_xyz


                    You’re in dreamland. Licensed “plumbers”, unlicensed “plumbers” and home owners are making connections like this every day all over the world and people are being poisoned. I’m not overjoyed by some of the new products and technologies either, but “TIME MARCHES ON” (apparantly without you)

                  • #287024
                    Avatar photoSylvanLMP

                      Art WE AGREE time does march on.

                      But why should quality suffer?
                      Today we have plastic garbage for drainage YET my accounts allow me to decide which material to install.

                      Yesterday I installed a floor drain with an inside LEAD and oakum joint (caulked) for 21/2 hours labor and less than $78.00 of materials I was able to charge just over $1,450. But then again I did use a proven time tested connection.

                      I like this new plastic heating Ideas as it creates more work for us as they fail.

                      Imagine Art if you and I are the only 2 plumbers left in the world who still can lead wipe. Think of the money we could roll in.

                      Last year I had to wipe ONE 4″ lead joint in an 1860s Brownstone building Imagine you making over $2,200 for ONE HOURS labor.

                      As more and more Billy butt cracks get into this trade and more home owners end up destroying their homes do to faulty projects can make a fortune picking up the pieces.

                      A few years back an NYC police officer not only managed to get himself killed BUT his entire family including his 2 children 18 months and 2 month old plus his young wife.

                      All he did was have a friend through a friend install a hot water heater that he bought in a home center.

                      Seems the installer didn’t know about metalbestos (double wall piping) and this single wall pipe set the one family frame house on fire.
                      The neighbors heard the screams for a full 20 minutes before the entire home was engulfed in flames

                      A few weeks ago another family died as the installer of the hot water heater figured who needs a 4″ flue pipe when the 2″ one is so much cheaper ($12)The installer was a brother in law to the victims

                      Today plumbing is taking one giant step backwards, BUT us great plumbers can and do make over $1000 PER DAY one man.(7 hours) The key is knowledge of the old and NEW and keeping abreast as much as possible.

                      When plumbing stops being fun color me gone. I was semi retired since I was 34 and retired completly at 40 BUT came back into plumbing as it is fun learning something everyday.

                      Being independent is a great feeling and knowing we can afford to stop any time is even a better feeling . Knowledge is indeed wealth Have a great week end guy.

                    • #287025
                      Avatar photokenny b

                        Art, Sylvan may out type you, but facts are facts in todays world. Your points are well taken and acknowledged by me and my state code. But what do I know, I always thought New York City was in New York State.

                        A N.Y.State plumber, Excuse me!
                        A N.Y.State LMP
                        But not a Great one,Just honest I don’t make $1000.00 a day.

                      • #287026
                        Avatar photokenny b

                          Art, your views are well known and acknowledged in my state code. sylvan may out type you but fact is fact. (maybe) I always thought N.Y.City was in the state of New York.

                          A N.Y.State plumber, excuse me.
                          A N.Y.State LMP

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