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Compressed Air Velocity Calculator

Calculate the velocity of compressed air flowing through a pipe

Calculation Results

Air Velocity: 0 ft/min

Air Velocity: 0 m/s

About Compressed Air Velocity

What is Compressed Air Velocity?

Compressed air velocity refers to the speed at which compressed air moves through a pipe or duct. It’s a critical parameter in pneumatic system design, affecting both system efficiency and performance. Proper air velocity ensures efficient energy transfer while minimizing pressure drops and turbulence.

Compressed Air Velocity Formula

The formula to calculate compressed air velocity is:

V = (Q × 144) / (A × P × 0.0583 × (T + 460))

Where:

V = Air velocity (ft/min)
Q = Air flow rate (CFM – cubic feet per minute)
A = Cross-sectional area of pipe (in²)
P = Absolute pressure (PSIA – PSI absolute)
T = Temperature (°F)
144 = Conversion factor (in²/ft²)
0.0583 = Constant for air (lb/ft³ at standard conditions)
460 = Conversion factor from °F to Rankine

How to Calculate Compressed Air Velocity

Follow these steps to calculate compressed air velocity:

Measure or determine your air flow rate in CFM
Measure the internal diameter of your pipe
Calculate the cross-sectional area of the pipe (π × r²)
Note your system pressure (add 14.7 to gauge pressure to get absolute pressure)
Measure the air temperature in °F
Plug all values into the formula above
Calculate to find the air velocity in ft/min

Frequently Asked Questions

What is the ideal velocity for compressed air?

For most industrial applications, the recommended compressed air velocity is between 20-30 ft/s (600-900 ft/min). Higher velocities can cause excessive pressure drops and noise, while lower velocities may allow moisture to accumulate.

Why does compressed air velocity matter?

Proper air velocity is crucial because it affects system efficiency, pressure drop, and the ability to carry contaminants. Too high velocity increases friction and energy costs, while too low velocity can cause moisture accumulation and poor tool performance.

How does pipe diameter affect air velocity?

Pipe diameter has an inverse square relationship with air velocity. Doubling the pipe diameter reduces velocity by a factor of four (at constant flow rate). This is why proper pipe sizing is essential for efficient system operation.

Does temperature affect compressed air velocity?

Yes, temperature affects air density which in turn affects velocity. Warmer air is less dense, so at the same pressure and flow rate, velocity will be slightly higher than with cooler air.