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  1. #1
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    [Free] Venturi flow meter 1" internal diameter

    Greetings,

    straight to the point here is one of the version. I designed the venturi by following the ASME standard (ASME MFC-3M-1985)
    You can find my original upload on youmagine.com, refer to https://www.youmagine.com/designs/ve...ernal-diameter
    Technical drawing is included on youmagine.
    The parts is printable, but is hard. Considering the object height /base ratio is high, it is strongly suggest that you print a thick layer of brim. Else your base will just lift and your print will be completely ruined.

    -Instruction
    Rotate the venturi on the axial direction. Make sure the flat flange is at the bottom.
    Apply thick layer of brim

    large_Venturi_tube.jpgventuri.jpg
    Venturi_flow_meter.stl

  2. #2
    Super Moderator curious aardvark's Avatar
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    looks pretty simple to print.

    But what does it do ?

  3. #3
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    Quote Originally Posted by curious aardvark View Post
    looks pretty simple to print.

    But what does it do ?
    It's what they use whenever they need to know the flow rate of a fluide. It can be used in those water station for measuring the volume rate, or knowing how much steam the system has been fed in power plant. The version in cast iron, or machined steel cost a fortune and price can easily skyrocket in the thousand $, let alone the aerospace field that might go even in the 10k$.

    Our school couldn't afford venturi due to highcost, and, I saw the potential for small laboratory project using compressed air tool, blower testing, etc. Instead of spending stupid amount of budget on some items that might be used one or twice.

  4. #4
    Super Moderator curious aardvark's Avatar
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    so has it got internal valve or something ?
    Just trying to figger out how it measures flow :-)

  5. #5
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    Oh you measure basically the differential pressure. Anything can be improvised to measure the differential pressure,it just depends on how accurate you want your results to be. I tend to use water column as reference, then convert into Pascal.
    Then you input those value into the following equation based on the following scheme.
    The figure underneath, is basically the cross section of the venturi.



    Based on Bernouilli's equation and with some tweak, the result is as follow.

    Where A is the surface area, rho the density of the fluid and C is a flow correction. Typical venturi has a has a C value of 0.95(well .90 to )


    There are many ways to measure flow, from simpliest device to complexe device. The venturi is a simple device but cost just too much, somewhat due to complexe geometry shape for machining.


    In the industry and research, more people will tend to adopt the orrifice plate, since they care about cash and don't care about sacrificing pressure lost due to brutal geometry change that leads to formation of vorticities.
    Basically, it's a disk with a hole in it.



    The equation becomes more complicated, since you must add more correction factor , but again, you basically measure the differential pressure and input the value into the equation.
    Attached Images Attached Images

  6. #6
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    Oh and here's the link in case you want to know more.

    (Make sure you don't close the tabs, because it's basically for premium user and they enable for free for a few minutes)
    http://www.efunda.com/formulae/fluid..._flowmeter.cfm
    http://www.efunda.com/formulae/fluid..._flowmeter.cfm

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