Announcement

Collapse
No announcement yet.

expansion tank

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • expansion tank

    OK a buddy of mine has a dual check back flow preventer on the incoming water main.Calls me up and says he thinks the floor drains backing up.So i go out there floor drains fine.He says but i notice water around the drain at times.After looking around i realized that there's no expansion tank on the heater.I was always thought that if there's a back flow preventer u need to have an expansion tank.Anyway he has two heaters in line.ones 10 yrs old ones 5 yrs old .i would assume that the reason the one failed so soon was the added stress on the tank without an expansion tank.Now I've convinced him to replace the 10 yr old tank because it's starting to leak from the bottom and I'd not holding a consistent temperature. At the same time put an expansion yank on each water heater ...He's convinced that he would only need one but i have always thought that for every 40 gallons of heated water you would need at least a 2.5 gallon expansion tank.He has two 40 gallon heaters so would he be OK with one 5 gallon expansion tank or two 2.5 tanks one on each side.

  • #2
    Interesting Question. Yes it requires an expansion tank in most States that I know of. Here in Texas, we have a lot of homes that have two heaters installed either in Parallel or Series. All have just one 2.1 expansion tank. The only way that I would think that you would need two expansion tanks, is if there are check valves in place that would isolate water movement from one to the other. Don't forget to air the tank up to equal the pressure of the incoming water pressure. The factory presets them, and it is up to you to adjust it accordingly. I started using expansion valves here, We are having problems with the new E.P.A. water treatment guidelines and the Chloramine in the water is eating the bladders out at a rate 3 times the norm. I just used a watts calculator and it looks like you can use the PLT-5-m1, which is a 2.1 tank. This is based on 80 psi water pressure. Pretty cool chart.
    Watts Drainage Products - floor drain, floor sink, grease interceptor, cleanout, carrier, roof drain, trench drain, ProLine products and much more...
    "don't put that in your mouth, you don't know where it's been"

    Comment


    • #3
      Do you need expansion tanks on electric water heaters? All of mine are gas and I've always wondered.

      Comment


      • #4
        Yes. On Gas and Electric
        "don't put that in your mouth, you don't know where it's been"

        Comment


        • #5
          Consider using a Amtrol ST-12 expansion tank. The two heaters (40 gal ea.) would be sized as one 80 gal. If they are not isolated from each other forming separate closed systems. Sizing a thermal expansion tank properly requires several factors to be known. Starting temp of water to be heated,volume of water to be heated,temp of water after heating and incoming water pressure(should not exceed 80psi). This info is not complete but just offered as general knowledge.

          Comment


          • #6
            1 properly sized tank is all you need as long as there is nothing preventing flow to the tank from either heater. typically installed on the cold water inlet.

            make sure to properly support the tank as it gets heavy when full of water and the 3/4'' nipple will bend and break off from the tank. also a 3/4'' ball valve is a wise idea when the tank takes a dump. just make sure to exercise every ball valve on an annual basis.

            Rick.
            phoebe it is

            Comment


            • #7
              So, here is an expansion tank that is 3 years old. I put it in and set the pressure in accordance with the house pressure. If you are unaware, most of the country is starting to reduce the amount of Chlorine in the water, but they are adding ammonia. This is creating a product called Chloramine. It is eating rubber parts that are not EBDM. I cut this tank open to show another plumber about the problem, because he didn't believe me. FYI, Korky flappers and no other flapper that I know of are Chloramine Resistant.
              "don't put that in your mouth, you don't know where it's been"

              Comment


              • NHMaster3015
                NHMaster3015 commented
                Editing a comment
                Chloramine is making me a bunch of money right now.

              • Plumbingbyjay
                Plumbingbyjay commented
                Editing a comment
                I am making money, but I hate going back on things that I have already worked on. My goal is to make things last at least 10 years. Life as a Plumber, the only one's in the trades who can contain a living source.
            Working...
            X