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O-Rings & Valves: Chemical Compatibility

O-rings are used in many Quantachrome instruments as gas and vacuum-tight seals and valves have polymeric sealing surfaces. O-rings and valves are available in a variety of elastomeric materials and these differ in their compatibilities with different gases and vapors. Listed below are the O-ring and valve materials we most commonly employ and their relative ratings[1] for use with some common fluids.

S = suitable, Ss = suitable for short exposure (<48 hours)
N = not suitable, do not use.

Fluids which are deemed compatible, at least for short periods, with all elastomers listed are highlighted in bold.


  Fluid Name   Formula   Buna-N   EPDM   Viton   Kalrez
  Acetone   C3H6O   N  S   N   S
  Acetylene   C2H2   S  S   S   S
  Ammonia (dry)   NH3  S   S   N   S
  Argon   Ar  S  S  S   S
  Benzene   C6H6   N   N   S   S
  Butane   C4H10   S   N   S   S
  Carbon dioxide   CO2   S   S   S   S
  Carbon monoxide   CO   S   S   S   S
  Cyclohexane   C6H12   S   N   S   S
  Ethane   C2H6   S   N   S   S
  Ethanol   C2H5OH   Ss   S   S   S
  Helium   He   S   S   S   S
  Hexane   C6H14   S   N   S   S
  Hydrogen   H2   S   S   S   S
  Isopropanol   C3H7OH   S   S   S   S
  Krypton   Kr   S   S   S   S
  Methane   CH4   S   N   S   S
  Nitric oxide   NO   N   N   N   Ss
  Nitrogen   N2   S   S   S   S
  Nitrogen dioxide/tetroxide  NO2 (N2O4)   N   N   N   Ss
  Nitrous oxide  N2O   S   S   S   S
  Pyridine  C5H5N   N   S   N   S
  Sulfur dioxide (dry)  SO2   N   S   Ss   S
  Sulfur hexafluoride  SF6   S   S   S   S
  Xylene  C8H10   N   N   S   S
  Water  H2O   S   S   S   S


[1] This information has been compiled from the following sources: Cole-Parmer Parker Seal Group (O-ring Division), and Marco Rubber. This information refers to chemical compatibility only and does not imply suitability for use according to any other criteria.

If you do not see the fluid-elastomer pair of interest, please visit one of the following sites to determine suitability:

If you are unsure regarding what O-rings and valve types are used in your particular Quantachrome instrument or whether a fluid not listed here can be reasonably employed, please contact Quantachrome by filling out this contact form, emailing or calling our toll-free number 1-800-989-2476.

Always involve your health and safety management when using compressed gases, refer to the appropriate MSDS available from your gas supplier (not Quantachrome) and observe all safety precautions printed in the instrument operator's manual.

Quantachrome makes no express or implied warranties or guarantees regarding the information above. Quantachrome cannot be responsible for conditions of use of any gases and shall not be liable for any injury, damage or loss resulting from the use of any of the listed materials above.