Technical Brief: Vacuum System Design:Choosing The Correct Sized Tubing
© 2016 Vaccon Company
9 Industrial Park Road, Medway, MA 02053 Phone: (508) 359-7200, US (800) 848-8788 Fax: (508) 359-0177Visit Us Online at www.vaccon.com or email us at [email protected]
Technical Brief: How Vacuum Pumps WorkTechnical Brief: Vacuum Termsand Definitions
When comparing Vaccon venturi vacuum pumps to our competitors…Compare vacuum flows in the working range (9”Hg - 27”Hg) where work is actually accomplished. Comparing vacuum flow at 0”Hg is likecomparing the output of a compressor at 0 PSI. High flow at 0”Hg is meaningless…no work is done at 0”Hg. Consider the analogy of an aircompressor to a vacuum pump, suppose a compressor dealer claims a compressor generates 1,000 CFM at 0 PSI (exaggeration) but only 1CFM at 80 PSI…is the 0 PSI flow rate meaningful? The same holds true for a vacuum pump flow rating at 0 ”Hg. 1st - Compare MaximumVacuum Level, 2nd - Compare Air Consumption (Operating Pressure is not important), 3rd - Compare Vacuum Flow in the working range
Vacuum flows for a VP80-200H pump(SCFM in blue, LPM in green)
Working Range
Air Consumption:The volume of compressed air required to power the pump.
Atmospheric Pressure:The atmosphere that surrounds the Earth can be considereda reservoir of low pressure air. Its weight exerts a pressure thatvaries with temperature, humidity and altitude.
Barometer:A device usually filled with mercury that measuresatmospheric pressure.
Compressed Air Considerations:1HP @ 80 PSI generates approximately 4 SCFM of flow.
Ejectors, Generators, Transducers, Venturi’s:All of these are different names for air powered vacuum pumps.
Standard / Average Atmospheric Pressure @ Sea Level:29.92”Hg or [760 mmHg].
Vacuum Flow:The volume of free air induced by the vacuum pump per unit oftime, expressed as standard cubic feet per minute – SCFM or[liters per minute - LPM]. The vacuum flow through Vacconpumps is shown graphically on the next page.
Vacuum Force:Equal to the vacuum level times the area of the vacuumsurface (i.e. holding area of a Vacuum Cup).
Vacuum Terms and DefinitionsVacuum Level:The magnitude of the suction created bythe vacuum pump. The unit of measure isinches of Hg (“Hg) or (mbar). Vacuum levelis affected by elevation and barometricpressure. For each 1,000 feet of elevation,vacuum level decreases by 1” Hg. Vacuumlevels for Vaccon venturi pump models areas follows:
L 0-10” Hg, [0 - 339 mbar] low vacuum/high flow applica�ons
M 0-20” Hg, [0 - 677 mbar] medium vacuum/high flow applica�ons
H 0-28” Hg, [0 to 948 mbar] high vacuum/standard flow applica�ons
HiVac series pumps are capable of 29.5” Hg (999 mbar)
50 mm Hg = 1 PSI 29.92" Hg = 760 Torr
1 mm Hg = 1 Torr 29.92" Hg = 100 kPa
1" Hg = 25.4 mm Hg 14.7 PSI = 100 kPa
2" Hg = 1 PSI 14.7 PSI = 29.92" Hg
29.92" Hg = 760 mm Hg 14.7 PSI = 760 mm Hg
Important Vacuum Conversions
0 " Hg 3 " Hg 6 " Hg
5.40 4.70 3.85
0 mbar 102 mbar 203 mbar
152.90 133.10 109.00
9 " Hg 12 " Hg 15 " Hg 18 " Hg 21 " Hg 24 " Hg 27 " Hg 28 " Hg
3.30 3.00 2.60 2.10 1.60 1.20 0.60 0.00
305 mbar 406 mbar 508 mbar 609 mbar 711 mbar 814 mbar 914 mbar 948 mbar
93.40 85.00 73.60 59.50 45.30 34.00 17.00 0.00
% Vacuum " Hg mm Hg (Torr) bar PSI
0 (atmosphere) 0 760.00 1.0 14.70
10 3 692.31 0.9 13.23
20 6 615.38 0.8 11.76
30 9 538.46 0.7 10.29
40 12 461.54 0.6 8.82
50 15 384.62 0.5 7.35
60 18 307.69 0.4 5.88
70 21 230.77 0.3 4.41
80 24 153.85 0.2 2.94
90 27 76.92 0.1 1.47
100 29.92 0.00 0.0 0.00
Conversion Chart - Vacuum vs. Pressure
© 2016 Vaccon Company
9 Industrial Park Road, Medway, MA 02053 Phone: (508) 359-7200, US (800) 848-8788 Fax: (508) 359-0177Visit Us Online at www.vaccon.com or email us at [email protected] Us Online at www.vaccon.com or email us at [email protected]
Application Note: Vacuum Termsand Definitions
Air Supply
Exhaust
Vacuum
Vacuum Flow
VDF Series
Air Supply
Exhaust
Vacuum
Vacuum Flow
CDF Series
Air Supply
Exhaust
Vacuum
VPI Series
J Series
Air Supply
Exhaust
Vacuum
Vacuum Flow Illustratedfor Vaccon Products
VP Series
Air SupplyExhaust
Vacuum
RTM Series
Vacuum
Exhaust
Air Supply
DF Series
Air Supply
Exhaust
Vacuum
Vacuum Flow
These images show the path of vacuum flow throughVaccon pumps, with air supply, vacuum and exhaustports denoted
Vacuum Flow
Vacuum Flow
Vacuum Flow
Vacuum Flow
