Fomblin® VAC PFPE - FAQ

Frequently Asked Questions

What is the Difference Between Fomblin® PFPE Oil and Fomblin® VAC?

Fomblin® VAC fluids have been specially developed in order to combine narrow molecular weight range and controlled viscosity with an extremely low vapor pressure. Thus, they provide superior performance in high vacuum applications, especially systems exposed to aggressive gases. Solvay Specialty Polymers is able to provide these grades due to its edging technology where distillation step makes us able to design tailor-made products according customer requirements.

What is the Difference Between Fomblin® Y LVAC and Fomblin® Y HVAC?

Fomblin® Y LVAC grades are ideal for use in vacuum pumps as sealing and working fluids especially in those systems exposed to aggressive gases.

Fomblin® Y HVAC combines narrow molecular weight range and controlled viscosity with an extremely low vapor pressure. Thus, they provide superior performance in high vacuum applications as working fluid specially for diffusion pumps.

Based on My Vacuum Pump, which Fomblin® VAC Grade Should I Use?

 Fomblin® Y LVAC GradesFomblin® Y HVAC Grades
Application06/614/616/625/618/825/940/11140/13
Rotary pumps: sealing & lubricant fluid     
Turbomolecular pumps: lubrication       
Root pumps: lubrication     
Diffusion pumps: working fluid    

What is the Kinematic Viscosity Behavior vs. Temp. of Fomblin® VAC Fluids?

Fomblin® Y LVAC viscosity vs. temperature chart

Fomblin-Y-LVAC-viscosity-vs-temperature-600px

Fomblin® Y HVAC viscosity vs. temperature chart

Fomblin-Y-HVAC-viscosity-vs-temperature-600px

What is the Vapor Pressure Behavior vs. Temperature of Fomblin® VAC Fluids?

Fomblin® Y LVAC vapor pressure vs. temperature chart

Fomblin-Y-LVAC-viscosity-vs-temperature-600px

Fomblin® Y HVAC vapor pressure vs. temperature chart

Fomblin-Y-HVAC-vapor-pressure-vs-temperature-600px

Are Fomblin® VAC Additivated Grades Commercial?

Rust Preventive formulation (LVAC RP) was studied to reduce or prevent rusting when huge amount of water vapors has to be pumped or when metal surfaces of the pump are exposed to moisture. An optimum concentration of additive in Fomblin® Y LVAC grades was studied to provide protection against rust and at the same time to guarantee the physical properties and the vacuum performance of the grade.

Anti-rust property evaluation

  • Fog chamber (method ASTM B117)
  • Conditions: temperature = 45 °C, humidity = 90 %

SampleFluidFog Chamber TimeCorrosion DegreeFog Chamber TimeCorrosion Degree
Cast ironY LVAC40 mins51 hour> 5
Low carbon steelY LVAC40 mins41 hour5
Cast ironY LVAC RP24 hours096 hours1 – 2
Low carbon steelY LVAC RP24 hours096 hours2

Rating
0 – No corrosion
1 – Not more than three small spots of corrosion
2 – Small areas of corrosion covering up to 1 % of the surface
3 – Small areas of corrosion covering from 1 % to 5 % of the surface
4 – Small areas of corrosion covering from 6 % to 10 % of the surface
5 – Small areas of corrosion covering more than 10 % of the surface


Fomblin® PFPE anti-rust additivated grades maintain the same viscosity and vapor pressure behavior than not additivated ones. As the following charts show:

Fomblin® Y LVAC RP – viscosity vs. temperature chart

Fomblin-Y-RP-LVAC-viscosity-vs-temperature-600px

Fomblin® Y LVAC RP – vapor pressure vs. temperature chart

Fomblin-Y-RP-LVAC-vapor-pressure-vs-temperature-600px

Are Fomblin® Y LVAC Fluids Food Grade Approved?

Fomblin® Y LVAC 25/6 is NSF approved with the intended use described below:

  • H1: General, incidental contact
  • H2: General, no contact
  • HX-1: Ingredients for use in H1 lubricants, incidental contact
  • HX-2 Ingredients for use in H1 lubricants, no contact