Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Vacuum and Measurement of Flow

Measuring volume flow in vacuum

Sponsored Links

For standard or normal pressure it is common to measure flow in

  • standard cubic feet minute - scfm - imperial units
  • normal metric liter per second - nl/s - metric units

In vacuum the air or gas is expanded and it is common to use

  • actual cubic feet minute - acfm - imperial units
  • actual metric liter per second - al/s - metric units

Since the gas is expanded, actual volume flow is greater than standard volume flow for the same amount of gas.

The flow volume can be converted from standard volume flow to actual volume flow by the expression:

qa = qs (29.92 / p) ((t + 460) / 520)                                  (1)

where

qa = actual volume flow (acfm)

qs = standard volume flow (scfm)

p = actual pressure (in Hg)

t = temperature (oF)

Conversion Factor from scfm to acfm (or nl/s to al/s)
PressureTemperature (oF)
in Hg absolutein Hg gaugekPa absolute0306090120150
29.92 0.00 101.42 0.88 0.94 1.00 1.06 1.12 1.17
28.92 1.00 98.03 0.92 0.97 1.03 1.09 1.15 1.21
27.92 2.00 94.64 0.95 1.01 1.07 1.13 1.20 1.26
26.92 3.00 91.25 0.98 1.05 1.11 1.18 1.24 1.30
25.92 4.00 87.86 1.02 1.09 1.15 1.22 1.29 1.35
24.92 5.00 84.47 1.06 1.13 1.20 1.27 1.34 1.41
23.92 6.00 81.08 1.11 1.18 1.25 1.32 1.40 1.47
22.92 7.00 77.69 1.15 1.23 1.31 1.38 1.46 1.53
21.92 8.00 74.31 1.21 1.29 1.36 1.44 1.52 1.60
20.92 9.00 70.92 1.27 1.35 1.43 1.51 1.60 1.68
19.92 10.00 67.53 1.33 1.42 1.50 1.59 1.68 1.76
18.92 11.00 64.14 1.40 1.49 1.58 1.67 1.76 1.86
17.92 12.00 60.75 1.48 1.57 1.67 1.77 1.86 1.96
16.92 13.00 57.36 1.56 1.67 1.77 1.87 1.97 2.07
15.92 14.00 53.97 1.66 1.77 1.88 1.99 2.10 2.20
14.92 15.00 50.58 1.77 1.89 2.01 2.12 2.24 2.35
13.92 16.00 47.19 1.90 2.03 2.15 2.27 2.40 2.52
12.92 17.00 43.80 2.05 2.18 2.32 2.45 2.58 2.72
11.92 18.00 40.41 2.22 2.37 2.51 2.65 2.80 2.94
10.92 19.00 37.02 2.42 2.58 2.74 2.90 3.06 3.21
9.92 20.00 33.63 2.67 2.84 3.02 3.19 3.36 3.54
8.92 21.00 30.24 2.97 3.16 3.35 3.55 3.74 3.93
7.92 22.00 26.85 3.34 3.56 3.78 4.00 4.21 4.43
6.92 23.00 23.46 3.82 4.07 4.32 4.57 4.82 5.07
5.92 24.00 20.07 4.47 4.76 5.05 5.35 5.64 5.93
4.92 25.00 16.68 5.38 5.73 6.08 6.43 6.78 7.13
3.92 26.00 13.29 6.75 7.19 7.63 8.07 8.51 8.95
2.92 27.00 9.90 9.06 9.66 10.25 10.84 11.43 12.02
1.92 28.00 6.51 13.79 14.68 15.58 16.48 17.38 18.28
0.92 29.00 3.12 28.77 30.65 32.52 34.40 36.27 38.15
0.82 29.10 2.78 32.28 34.38 36.49 38.59 40.70 42.80
0.72 29.20 2.44 36.76 39.16 41.56 43.95 46.35 48.75
0.62 29.30 2.10 42.69 45.47 48.26 51.04 53.83 56.61
0.52 29.40 1.76 50.90 54.22 57.54 60.86 64.18 67.50
0.42 29.50 1.42 63.02 67.13 71.24 75.35 79.46 83.57
0.32 29.60 1.08 82.71 88.11 93.50 98.89 104.29 109.68
0.22 29.70 0.75 120.31 128.15 136.00 143.85 151.69 159.54
0.12 29.80 0.41 220.56 234.95 249.33 263.72 278.10 292.49
Sponsored Links

Related Topics

Related Documents

Tag Search

  • en: vacuum flow measurement air
Sponsored Links

Search the Engineering ToolBox

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the SketchUp Pro Sketchup Extension Warehouse!

Translate this page to
About the Engineering ToolBox!
.

close

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Scientific Online Calculator

Scientific Calculator

1 15

Sponsored Links