The formula to calculate the velocity from GPM is:
\[ V = \frac{\text{GPM}}{7.481 \times A \times 60} \]
Where:
To calculate the velocity from gallons per minute, divide the GPM by 7.481, divide again by the cross-sectional area of flow, then finally, divide by 60. This will give you the velocity in feet per second.
Example:
Calculation:
\[ V = \frac{100}{7.481 \times 2 \times 60} = 0.11 \text{ ft/s} \]