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When is this calculator suitable?

You can use this calculator for air flow rate and pressure drop calculation of flow through
a round closed pipe.
You can use this calculator for laminar and turbulent flow regime.

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What are the calculator restrictions?

A temperature of the gas is considered to be constant, regardless of created pressure drop.
This assumption is valid only for relatively long pipelines without any sudden changes and
pipe thermal insulation. During slow, steady flow, if the temperature of the fluid drops
due to the pressure drop, this calculation model assumes that fluid takes heat from the
surrounding. This heat taken from the surrounding keeps the temperature of the flow in the
pipeline constant. This heat taken from the surrounding keeps the temperature of the flow
in the pipeline constant.

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How is the calculation executed?

The calculator uses a pressure drop equation for isothermal flow. To calculate the
pressure drop, the calculator performs friction factor f and minor resistance coefficient
K calculation, as well as the mean velocity of the flow on the pipe start and the pipe end.

The calculator includes Reynolds number (Re) calculation. Also, the calculation is
performing friction losses (f) and minor losses factors (K), needed for
pressure drop calculation.

Calculator presents values of Reynolds number and flow regime - laminar or turbulent,
as well as calculated velocities on the pipe start and the pipe end.

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When is this calculator not relevant?

This calculator is not suitable for adiabatic flow when the temperature is changing due to the
change of pressure. It means that you can't use this calculator where you expect for sudden
changes pressure due to flow restrictions, sudden change of the flow direction and similar
conditions.
The calculator is not considering a change of the height in the calculation.

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What else has to be known to perform the calculation?

For pressure drop calculation you must enter flow rate and pipe diameter.
For flow rate calculation, you must enter pressure drop and pipe diameter also.

# Need a helping hand?

If you need a quick calculation, but you are not still familiar how to use the calculator, you
can order calculation service from the calculator developer.