Orifice flow calculation

Calculation flow trough orifice

Calculation flow trough orifice

Here is an online calculator of the flow through the orifice. Using this chart you can determine both flow through existing orifice or estimate the orifice diameter for required flow.


value imperial metrical
Inlet pressure, pin: psi bar
Consumer's work pressure, pw: psi bar
Pressure drop across orifice, Δp=pin−pw: psi bar
Required flow trough orifice, Q: GPM LPM
Oil Specific Gravity, SG: See table for reference
Orifice coefficient, cd: See table for reference
Orifice Diameter, D: in mm


How to use this chart.

Just change any values in the input fields, others will be re-calculated automatically.

Like an option, you can use Characteristic curves for calibrated orifices (PDF, 38Kb)

1 Comment

  1. Pablo

    Does this calculation work also for lubrication oil, in a range between 50 and 70 deg C where the dynamic viscosity almost changes by a factor of 2?


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