Total Flow Area (TFA) - Formula

Total Flow Area (TFA) is summation of nozzle areas which fluid can pass through. When you consider about the TFA, you need to count all nozzles that you have in a bit or a reamer.

Basically you can determine flow area with a simple circle area formula.

Where;

Area in square inch

π is a constant which approximately equates to 3.1429.

D is diameter in inch

Let’s make it easier for our life. Normally, a diameter of nozzle is reported in xx/32 inch. For example, a bit has 3 nozzles and each one of them has size of 20/32 inch.

The formula above can be simplified like this.



Where;

Area in square inch

N is nozzle size in number/32 inch.

In order to find the total flow area of each bit or reamer, you must add all area of each nozzle.

For instant, you use a bit that has a total of 5 nozzles. Three nozzles have a diameter of 10/32 inch and other 2 nozzles are 12/32 inch diameter. Determine the total flow area (TFA) of the bit.

By the definition, you must sum every nozzle together in order to get the TFA; therefore, you can apply the formula above into this form.



Total flow area = 0.451 square inch.

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