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expansion tank sizing

bill_105
bill_105 Member Posts: 429
Is it possible to oversize an expansion tank? I had a brand new #60 tank charged to 12 lbs. and the relief valve leaked on two different boilers. After installing a, " By the book" tank, everything was fine. I'm thinking that diaphragm  just did not want to move. Words of wisdom are greatly apprecitated

Comments

  • If you`re sure

    about the acceptance volume it should have worked!



    Complete system content is the key!
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,852
    Diaphragms DO stick...

    I've had probably half a dozen of them in the stuck position, brand new, out of the box, from numerous and different maufacturers,



    Unless your system is doing heating AND cooling, it is virtually impossible to oversize the expansion tank.



    The ONLY thing lost in over sizing, is money...



    To UN stick a sticky diaphragm, hook the tank up to city water pressure and exercise it a few times. THen when pressurizing the new system, keep the pressure of the tanks a few pounds higher than the required fill. This will keep the diaphragm off the face of the tank.



    ME

    There was an error rendering this rich post.

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