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Using vacuum gauges to tune an oil burner

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HeatingHelp
HeatingHelp Administrator Posts: 651
edited December 2022 in THE MAIN WALL
imageUsing vacuum gauges to tune an oil burner

Using vacuum gauges to tune an oil burner

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  • GeoB
    GeoB Member Posts: 1
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    How do you arrive at .0086 for the fuel line diameter?
    mattmia2
  • mattmia2
    mattmia2 Member Posts: 9,850
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    I think the units for the tubing diameter is in feet but i still couldn't convert that to a common tubing size but the order of magnitude was right. This is why carrying units through your algebra and canceling them out is important. It also looks like it has parenthesis and variables used willy nilly which have a very specific algebraic meaning but isn't what is meant here which makes it very hard to interpret what was meant. It is a great concept but some editing by someone who understands what is meant and understands algebra would make it a lot easier to understand.
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    edited December 2022
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    .0086 is the volume of fuel in 3/8” copper tubing, .75 is a multiplier, based on what, I have no idea (probably based on their own testing).
    Also .258+3 = 3.258

    L =50' length
    Q=.60 gph firing rate
    H=4' Vertical height

    Lift Job
    V = (L * .0086 * Q) + (.75 * H)
    V= (50 * .0086 * .60) + (.75 * 4)
    V= (.258) + (3)
    V= 3.258

    Gravity (tank above burner)

    V = (L * .0086 * Q) - (.75 * H)
    V= (50 * .0086 * .60) - (.75 * 4)
    V= (.258) - (3)
    V= -2.742 (no vacuum, not factored in-filters, valves, etc).

    There was an error rendering this rich post.

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,157
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    I was taught a long time ago that 10 ft of horizontal 3/8" tube = 1" vacuum
    every foot of lift above the oil level was about 1" vacuum. So the 50 ft plus the 4 ft would be about 9" vacuum. I think that was for 2 pipe systems. I know that on a single pipe system the fuel flows much slower, so the friction loss in that 3/8" tube is much less.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?