Vacuum Conversion Factors

From Inches of Hg

to Atmospheres multiply by 0.0334211
to Bars multiply by 0.0338639
to mm of Hg multiply by 25.4 (Torrs=1mmHg)
to Grams/sq. cm multiply by 34.5316
to pounds/sq. ft multiply by 70.7262

From Atmospheres

to Bars multiply by 1.01325
to mm of Hg multiply by 760
to Grams/sq. cm multiply by 1033.23
to Pounds/sq. inch multiply by 14.6960
to Torrs multiply by 760
to Ft of H2O multiply by 33.8995


References and Data Sheets for Applications:

Cast Acrylic Properties
Better known by name brands such as Plexiglass, Acrylite, Chemcast, Methacrylates, etc. Acrylic plastic offers durability and is an excellent substitute for glass, acetate, polycarbonate or PVC when one is looking for transparency or translucency. It is half the weight of glass and 45% the weight of aluminum. Maximum Service Temperature, Air 65 – 112 °C 149 – 234 °F Average = 94.5 °C; Transmission, Visible 92%.


Specifying Degassing Vacuum and Temperature

Use these tools to help figure out what vacuum and temperature you should be specifying for your vacuum process:

Note that our most basic chambers are designed for 10-4 Torr operation. Refer to Table 1: Chamber Material Choices for more detail. In reality, the designed operational pressure will be adversely affected by, if nothing else, outgassing of customer’s product (and inadequate cleaning and preconditioning), and the customer should specify accordingly. Pumps should be chosen with ultimate pressures an order of magnitude better than the desired process pressure. Refer to our pump page for the ultimate pressure of available pumps (our most economical pumps are specified at 25 mTorr, whereas 10-4 Torr is the lowest rated pump without going to a Turbo system).


O-Ring Material Options

Material
Recommended Use
Not  Recommended For
Mechanical Properties
Buna-N   (Nitrile)
Standard: 70 Durometer Black
Temperature Range: -35 ºF to 250 ºF
Least Expensive / Readily Available
Silicone Greases  /  Oils
Water
Petroleum Oils / Fuels
Ethylene Glycol Fluids
Ketones (MEK)
Halogenated Hydrocarbons
Auto / Aircraft Brake Fluids
Strong Acids
Sunlight, Ozone,   Weathering
Good Wear Resistance
Good Compression Set  Resistance
Good Short-Term Resilience
Good Permeation Resistance
Viton ®    (Fluorocarbon Type A)
Standard: 75 Durometer Black Temperature Range: -15 ºF to 400 ºF
Vacuum
Most Acids  /  Chemicals
Halogenated Hydrocarbons
Di-Ester Lubricants
Petroleum Oils / Fuels
Silicone Oils / Greases
Ketones (MEK)
Auto / Aircraft Brake Fluids
Amines (Ammonia)
Acetone, Skydrol, Ethyl Acetate
Hot Water and Steam
Low Molecular Esters and Ethers
Good Wear Resistance
Excellent Comp. Set  Resistance
Moderate Short-Term Resilience
Excellent Permeation Resistance
Silicone
Standard: 70 Durometer Orange Temperature Range: -65 ºF to 450 ºF
Dry Heat
Wide Temperature Range
Sunlight, Ozone,   Weathering
Odorless and Non-Toxic
Ketones (MEK)
Acids
Silicone Oils
Brake Fluids
Poor Wear Resistance
Excellent Comp. Set  Resistance
Poor Short-Term Resilience
Excellent Permeation Resistance
EPDM   (Ethylene Propylene)
Standard: 70 Durometer Black Temperature Range: -60 ºF to 250 ºF
Sunlight, Ozone,   Weathering
Hot Water and Steam
Auto / Aircraft Brake Fluids
Some Acids and Bases
Ketones and Alcohols
Plumbing
Petroleum Oils
Fuels
Good Wear Resistance
Good Comp. Set  Resistance
Moderate Short-Term Resilience
Good Permeation Resistance
Chemraz ®  / Kalrez ®  / Simriz ® (Perfluoroelastomer)
Various Compounds   Designed for Specific Applications Temperature Range: -10 ºF to 615 ºF
High Temperature Resistance
Excellent Chemical Resistance
Low Out Gassing
Chlorine Wet/Dry
Petroleum Oil
Chlorinated Hydrocarbons
Molten metals
Gaseous Alkali Metals
Halogenated Freons/Fluids
Uranium Hexafluoride
Good Wear Resistance
Good Comp. Set  Resistance
Moderate Short-Term Resilience
Good Permeation Resistance
Material
Recommended Use
Not  Recommended For
Mechanical Properties
Neoprene ®  (Chloroprene)
Standard: 70 Durometer Black Temperature Range: -35 ºF to 250 ºF
Refrigerants (Freon)
Ammonia
Some Petroleum Oils
Dilute Acids
Silicone ester Lubricants
Ketones (MEK)
Gasoline
Auto / Aircraft Brake Fluids
Good Wear Resistance
Moderate Comp. Set  Resistance
Moderate Short-Term Resilience
Good Permeation Resistance
Urethane
Standard: 90 Durometer Translucent Temperature Range: -65 ºF to 200 ºF
Drive Belts
Some Petroleum Oils
Some Hydrocarbon Fuels
Oxygen / Ozone
Ketones (MEK)
Acids
Auto / Aircraft Brake Fluids
Chlorinated Hydrocarbons
Water
Excellent Wear Resistance
Poor Comp. Set  Resistance
Excellent Short-Term Resilience
Fluorosilicone
Standard: 70 Durometer Blue Temperature Range: -80 ºF to 450 ºF
Jet Fuel
Dry Heat
Wide Temperature Range
Some Petroleum Oils
Chlorinated Solvents
Ketones (MEK)
Phosphate Esters
Some Acids
Auto / Aircraft Brake Fluids
Amines (Ammonia)
Poor Wear Resistance
Moderate Comp. Set  Resistance
Moderate Short-Term Resilience
Poor Permeation Resistance
PTFE non-stick coating encapsulated
O-Ring Covered with PTFE non-stick coating Tube Usually Silicone or Viton ®
Depends on O-Ring Core
Chemical Resistance
Heat Resistance
Depends on O-Ring Core Good Wear Resistance
Good   Short-Term Resilience
Good Permeation Resistance
PTFE non-stick coating
Standard: Non-Elastic White Temperature Range: -250 ºF to 450 ºF
Chemical Resistance
Fuel Resistance
Low Coefficient of Friction
Non-Elastic Good Wear Resistance
Low Coefficient of Friction

Viscosity: Liquid Analogs –  @ Room Temperature (cP)

FLOW-Viscosity1