What is Air Quality Class?

Air Quality Class defines the cleanliness and dryness of compressed air supplied to pneumatic machines. It follows the international standard ISO 8573-1, which classifies air based on:

• Solid particles (dust and dirt)

• Water content (humidity)

• Oil content

For BestPack machines, we recommend ISO 8573-1 Class 7:4:4, which means the air is sufficiently clean and dry to protect pneumatic components and ensure reliable operation.

What is Peak Flow?

Peak Flow (or peak air consumption) is the maximum volume of compressed air the machine needs during operation, typically measured in:

• Liters per minute (L/min) or

• Standard Cubic Feet per Minute (SCFM)

Knowing peak flow helps you choose the right air compressor, air dryer, and filters to ensure the machine runs smoothly without air shortages.

How to Calculate Peak Flow for Pneumatic Cylinders

If you know the pneumatic cylinders your machine uses, you can estimate peak flow by calculating the air volume consumed per stroke, considering:

• Cylinder bore diameter (size)

• Stroke length (distance piston travels)

• Number of cylinders

• Cycle rate (strokes per minute)

• Operating pressure

• Whether cylinders actuate simultaneously or sequentially

• Single or double-acting cylinders (air used on one or both sides)

Example Calculation

Suppose your machine uses these cylinders:

Steps:

1. Calculate air volume per stroke for each cylinder side using:

   Volume=π×(Bore2)2×Stroke length\text{Volume} = \pi \times \left(\frac{\text{Bore}}{2}\right)^2 \times \text{Stroke length}Volume=π×(2Bore​)2×Stroke length

2. Multiply by 2 for double-acting cylinders (air consumed on both sides).

3. Find the largest volume per stroke among cylinders (peak usage).

4. Convert volume to standard conditions by adjusting for operating pressure (add atmospheric pressure).

5. Multiply by strokes per minute (cycle rate).

6. Convert liters per minute (L/min) to SCFM if needed (1 SCFM = 28.317 L/min).

Using the example data with 50 psi (≈3.45 bar gauge) operating pressure and 12 strokes per minute:

• Largest cylinder air volume per double stroke = ~1.1 L (at cylinder pressure)

• Convert to standard conditions:

  1.1×4.451=4.9 L1.1 \times \frac{4.45}{1} = 4.9 \text{ L}1.1×14.45​=4.9 L

• Multiply by cycle rate:

  4.9×12=59 L/min (standard conditions)4.9 \times 12 = 59 \text{ L/min (standard conditions)}4.9×12=59 L/min (standard conditions)

• Convert to SCFM:

  59÷28.317=2.1 SCFM59 \div 28.317 = 2.1 \text{ SCFM}59÷28.317=2.1 SCFM

Summary

• Recommended Air Quality: ISO 8573-1 Class 7:4:4

• Peak Flow: Depends on your machine’s pneumatic setup, but can be estimated using the method above.

If you need help with your specific machine’s air supply requirements, please contact BestPack support.