FLOW CALCULATION
  • Vote Up0Vote Down mobedifard May 2008
    Posts: 2
    Hi
    If an orifice is installed inversely how much error will take place in flow calculation?
  • 4 Comments sorted by
  • Vote Up0Vote Down dgcarver May 2008
    Posts: 3
    See the following links:
    http://www.afms.org/Docs/reg/Oil_and_Gas_Audit.pdf

    The following was copied from it

    Measurement Errors
    Anything that happens to the orifice plate ID will result in enlarging the hole,
    causing gas to pass unmeasured. Nicks, cuts, scratches, erosion, corrosion,
    bening, and so on will cause an increase in the plate ID, reducing the differential
    across the plant, and reducing the volume of measured gas.
    Examples
    - If something caused the ID of a 2” plate in a 4” meter run to increase by 1/8
    inch, the producer would give away 14% of the gas.
    - A notch of .05” will results in a loss of .6% of the gas.
    - A plate bent toward the gas flow 1/8” will result in a loss of 2.8%.
    - A coating of grease 1/16” on both faces results in a 15.8% loss.
    - A coating of grease 1/8” results in a 17.9% loss.
    - A coating of grease 1/4” results in a 24.4% loss.
    - If the orifice plate carrier is raised about 3/8” from bottom, 8.2% of gas is lost.
    - A slight dulling of the edge gives away .5%.
    - If the orifice edge is beveled just .01”, 2% is lost.
    - If the beveled orifice plate is put in backwards, it will result in a 20% lost.
    - One clean cut through the plate-sealing unit next to the tap holes gives away
    6.1% of the gas.
    - If a 4” meter run had deposits of only .2”, the loss is 1%.
    - If the deposits were .874” thick, the loss is 6.4%.
    - Liquid 1” deep in the bottom of the meter run tube results in the loss of 11.3%
    gas.
    - Grease and dirt deposits in the meter tube gives away 11.1% of the gas.

    Hope this helps.
  • Vote Up0Vote Down batplay4 May 2010
    Posts: 1
    This article is more beneficial to all. I know something about this post and get  many interesting things.
  • Vote Up0Vote Down dgcarver May 2010
    Posts: 3
    I assume you are referring to the posted article and are agreeing with it?
  • Vote Up0Vote Down tomalsk May 2010
    Posts: 1
    Air is very frequently used fluid for many applications in the industry. Air flow calculator can be applied for air flow through round pipe. Pressure drop or flow rate can be calculated, as temperature is considered to be constant.
    This calculator can be used for calculation of flow rate and heat power in liquified petroleum gas (propane-butane) pipe lines. Liquified petroleum gas is mixture of propane, butane and other components. This calculator is applicable for calculation of flow rate of gas and liquid phase and lpg heat power calculation (heat power is generated in gas furnaces). Calculator also can be used for calculation of clear propane or clear butane gas flow.
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