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tom_11 Member Posts: 58
It is a one pipe system, gravity return. the longest run of 2 inch pipe is 18 ft . thank you tom


  • tom_11
    tom_11 Member Posts: 58

    I have a weil mclain 368st oil fired boiler,n would i benfit in anyway by installing a vapor stat,insted of a pressuretrol? if so what be the setting for the vaporstat. thanks tom
  • Brad White
    Brad White Member Posts: 2,398

    Not knowing your system extent or type, there are some variables. But even a reasonable one or two pipe steam system can operate at between 8 and 10 ounces cut-out pressure.

    Think of your piping and steam carrying capacity at a certain pressure drop. Many old systems were designed for between 1 and 4 ounces pressure drop per 100 equivalent feet of pipe. If your longest run of piping is 50 feet with six elbows, you are probably at 100 equivalent feet or less, as a point of reference. That may take just four ounces, with the return being by gravity.

    Two-Pipe systems can do even better because of the separate return path for the condensate.
    "If you do not know the answer, say, "I do not know the answer", and you will be correct!"

    -Ernie White, my Dad
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