SPI Supplies brings you only the highest quality in high vacuum greases. We have tried to provide you with information to make an informed decision as to which high vacuum grease will meet your requirements. Tell us if you have a high vacuum grease requirement that is not being covered, perhaps we can help you!
Always keep in mind system compatibility when selecting a vacuum grease. There should be compatibility between the fluid being used in a diffusion pump the grease used on "O" rings. If using a Fomblin® fluid in the diffusion pump, use one of the fluoropolymer based vacuum greases (Such as VAC3® or Braycote®). If Santovac® 5 is being used in the diffusion pump we recommend the selection of Santovac 5 Vacuum Grease.
When it comes to "O" rings fluoropolymer based elastomers compatible with the three broad classes of greases namely, hydrocarbon, silicone, and perfluorinated polyether/PTFE based greases. Other synthetic elastomers are usually, but not always, compatible with hydrocarbon greases except EPDM. Silicone greases are also generally compatible with most synthetic elastomers except silicone and fluorinated silicone (fluorosilicone) rubbers. It is important to take into consideration the chemistry of the pump fluid used if a diffusion pumped system and not just the composition of the "O" rings. A compromise in order to achieve other specific characteristics such as inertness of the grease, or use at cryogenic temperatures.