Pressure Drop - Airbrush Guru

Pressure Drop

The difference between static and dynamic pressure on a compressor’s pressure gauge.

In-Depth

Static pressure is the reading before you start the air flowing.  Dynamic pressure is the the reading after you start air flowing.  Because the dynamic pressure is always lower it’s called a pressure drop.

The size of the drop depends on the size and length of the airhose you’re using.

  • Shorter hose = smaller pressure drop
  • Longer hose = greater pressure drop
  • Bigger inner hose diameter = smaller pressure drop
  • Smaller inner hose diameter = greater pressure drop

Why is it important?

Pressure drop is more important the bigger your air system is.  The more people, stations, and equipment you use off of one system the more important it is to know that you’re getting the right amount of air to any one station to do the required job.

Pressure Drop Chart

10′ Length
Air Hose
15′ Length
Air Hose
20′ Length
Air Hose
25′ Length
Air Hose
50′ Length
Air Hose
1/4 Inch Inner Diameter Air Hose
@ 40 PSI 8 9.5 11 12.75 24
@ 50 PSI 10 12 14 16 28
@ 60 PSI 12.5 14.5 16.75 19 31
@ 70 PSI 14.5 17 19.5 22.5 34
@ 80 PSI 16.5 19.5 22.5 25.5 37
@ 90 PSI 18.75 22 25.25 29 39.5
5/16 Inch Inner Diameter Air Hose
@ 40 PSI 2.75 3.25 3.5 4 8.5
@ 50 PSI 3.5 4 4.5 5 10
@ 60 PSI 4.5 5 5.5 6 11.5
@ 70 PSI 5.25 6 6.75 7.25 13
@ 80 PSI 6.25 7 8 8.75 14.5
@ 90 PSI 7.5 8.5 9.5 10.5 16

*Note: I totally lifted this chart wholesale from the Anest-Iwata pressure drop chart.