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How cold for above-ground LP tanks to have issues?

sunlight35
sunlight35 Member Posts: 35
What's the typical low temperature for above-ground propane tanks not able to provide sufficient gas pressure needed for boiler? My boiler requires a minimum pressure of 10 w.c.

Comments

  • GroundUp
    GroundUp Member Posts: 1,885
    As long as you keep it above 5% full, you'll never see weather cold enough to cause problems.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,405
    What @GroundUp said

    Above ground tanks are quite common. Not an issue
  • Oliveone
    Oliveone Member Posts: 7
    That funny :)
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,646
    There is a formula for wetted surface of the tank (how full it is and type of tank), outside temperature, and btu/hr draw of vapor. 

    Technically, at -45F the liquid will not vaporize. 
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
    mattmia2
  • Zman
    Zman Member Posts: 7,559
    Above ground tanks usually don't have issues. I do have a client with a 4,000 gallon tank and over 6,000,000 attached load in climate zone 7. They have issues and need to run a vaporizer to make it work.
    How big is the tank and boiler?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,405
    Yes the tank has to have enough surface area to be able to absorb heat to vaporize the liquid based on the connected load
  • Robert_25
    Robert_25 Member Posts: 527
    It depends on your btu load, and how full the propane tank is.  Google "propane tank vaporization chart" and you will see what I mean.  

    At -45F you could store the propane in a 5 gallon pail.  
  • sunlight35
    sunlight35 Member Posts: 35
    Thanks, I think I was mistaken w.c. for psi.
  • hot_rod
    hot_rod Member Posts: 21,974
    Zman said:

    Above ground tanks usually don't have issues. I do have a client with a 4,000 gallon tank and over 6,000,000 attached load in climate zone 7. They have issues and need to run a vaporizer to make it work.
    How big is the tank and boiler?

    I was on the maintenance team at Snowbird resort when it was first built, all LP boilers. The vaporizers were in a concrete vault in an avalanche path. Talk about a scary appliance to work on.
    They finally ran a NG line up the canyon.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Zman