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Expansion tank brackets (hr)

Dale
Dale Member Posts: 1,317
Good looking work as usual for you. HR, did you braze an iron elbo to the angle iron or is that a steel elbo welded on? And, with the electric water heater used as a source do you still run the power through the electric water heater high limit and will a high limit trip start the system pump? Leaving the regular T&P relief in place is a good idea since there must be 2 separate way to keep the water from getting hotter than 210F in a water heater.

Comments

  • hot_rod
    hot_rod Member Posts: 21,815


    I built these with some steel angle iron. A couple lag bolts fasten the bracket to the wall for support. A Dahl mini ball valve, with the handle turned to the rear, allows easy replacement.

    hot rod

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    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Jackchips
    Jackchips Member Posts: 344
    Nice work,

    as usual, HotRod.

    Innovative thinks like this always remind me of my late, talented, Father-in-law.
  • Dan Peel
    Dan Peel Member Posts: 431
    Fun stuff..

    I do love modular construction.
    We've started to eliminate shutoffs ahead of the expansion tanks.
    Once the CDN B214 code comes in we can't use them without removing handles.
    Electric water tanks for buffers or hydronics only are gone too.
    Guess we'll just play while we still can. It's soon be a euchre deck.........Dan

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  • Arthur
    Arthur Member Posts: 216
    Expansion Tank brackets

    These look nice but I have always considered it bad practice to fit a valve between the tank and the heat generator (Boiler) as some half wit could turn the valve off after the I have left the installation and then the system would have no expansion.
    I've always tried to make installation idiot proof as much as possible.
    A tank would seldom need removal or replacement and the system could always be drained for this.
  • ScottMP
    ScottMP Member Posts: 5,884
    The other view

    I happen to feel the other way. Diaphragm tanks seem to have a life of about five years or so. Shorter if another component fails and stress's the tank. The ability to replace the tank on a night service call without draining the whole system is a big plus.

    We install all our tanks with shut-offs and have yet to have a HO or anyone else, shut it off by mistake.

    We seem to find the problem pretty quickly when they do fail and I think this problem will also show up very quickly if it is shut-off.

    JMHO

    Scott

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  • hot_rod
    hot_rod Member Posts: 21,815
    Expansion tanks??

    I have a bunch of my smaller systems running without expansion tanks! The small 2 and 6 gallon electric water heater floor warming systems, I have done. As long as the pressure stays below the 30 lb. relief valve setting, is there a reason to have an expansion tank??? Fill them with cold (50 degree) water at 8 lbs, and they run up to about 16-18 at 140 degrees.

    In the unlikely event of a "stuck on" element I have both the 30 lb relief, and the factory installed T&P valve (which I leave in the tank) for protection.

    Years ago I toured a bunch of jobs in Colorado. Edwin Mauer, intregued me with his Polaris systems (radiant only)running without expansion tanks. The pex tubing would handle the expansion, he claimed. I think Dan wrote about these systems recently, also.

    Yes it is a good idea to remove the handle, and hide or discard them, when using isolation on expansion tanks. Unfortuantly they are not removable on this particular valve. I'm fine using a cresent on the stem, where the handle has been removed. Few homeowners would reconize that when looking at a ball valve.

    hot rod

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    Bob "hot rod" Rohr
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    Living the hydronic dream
  • Arthur
    Arthur Member Posts: 216
    Expansion tanks should last longer.


    I am a bit puzzled as to why the your tanks only last such a short time. I recently removed 2 big steam boilers 250Kws each and replaced them with a gas fired low pressure hot water boiler from the same site 175Kw which was over 15yrs old and the existing tank was as good as new. Fired up no problem at all.The plant had a reduced load which is why we could fit the smaller boiler.
    I don't ever remember having to replace an expansion tank but I guess one can always find a faulty one.
    The brand I use over here is mostly 'Pneumatex' made in Switzerland. These a full bladder type as against the cheaper half bladder type.
    What actually goes wrong with the tank? bladder burst or steel corrode though?
    Most of the problem I've seen on installations has been the tendancy to fit too small a tank and or the pressure in the tank being incorrect(mostly too high). This results in the pressure varying too much from cold to hot.
    With the half bladder it is very important to pipe so the tank is always full of water while with the full bladder ones it doesn't matter so much.
  • hot_rod
    hot_rod Member Posts: 21,815
    good questions

    Yes I leave all the electric tank components in place. I add a 30 lb relief and a Guard Dog LWC. This gives me plenty of protection. Actually what's the worse that can happen?? You dry fire the tank, ruin the element. Elements are cheap! I do like the pressure protection peace of mind offered by the dual relief valves.

    I also have a couple electric hw tank systems running at line pressure 40- 60 lb. Why not, all the components are listed to handle the pressure. Just use an approved backflow device at the fill tie in, and let it run. Water heater tanks are listed to 150 lbs, tested to 300!

    hot rod

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    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • hot_rod
    hot_rod Member Posts: 21,815
    Death by corrosion

    Failed bladder tank is most often caused by using them on non barrier tube systems. Polybutylene radiant systems will eat tanks like crazy. If you use non barrier tube spend the extra bucks and use a DHW expansion tank. (make sure you adjust the precharge pressure :) ) These are epoxy lined.

    Same with early rubber tube systems, solar roll and early Entran. If you are regularly replacing exp. tanks look further. The problem is generally not the tank!

    The other problem is not balancing the ph of the water in the system. Use of hydronic system inhibitors will make a lot of these nuisence problems disapper! Extended pump life, better heat transfer, longer life for cast iron and other ferrous components.

    hot rod

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    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Arthur
    Arthur Member Posts: 216
    Expansion tanks

    I presume that when you say non barrier pipe you mean oxygen barrier pipe? Guess we use slightly different terminology over here.lol. No offence meant.
    Actually the boiler and pipework wouldn't like it either unless you used a copper or s/s boiler,copper or poly pipe and a brass pump too.
    Yes Air is one of the worse if not the worse cause of corrision in a closed circuit heating system. Which is why I would not drain a system any more than I can help as every time you drain you introduce fresh water (with air) into the system.Best way with nonbarrier pipe is to use a heat exchanger between the 2 systems.
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