In the vacuum pump ,no matter rotay vane vacuum pump or rotary piston vacuum pump , vacuum pump oil not only as a medium for vacuum, also plays a role of lubrication, cooling and sealing of mechanical sore spot.
1. The very low vapour pressure
This is the most important performance of the vacuum pump oil, due to the vacuum pump requires a high vacuum degree, generally with paraffin base oil, narrow fractions for oil diffusion pump, low vapor pressure of the silicone oil can also be used or other synthetic oil.
2. The proper viscosity and good viscosity-temperature characteristic
Vacuum pump cavity content changing and form exhaust function, changing requirements should have appropriate viscosity lubricating oil and viscosity-temperature properties.
3. Good thermal oxidation stability
Vacuum pump to high speed development, because of the vane and the pump body high oil temperature rise, high speed of friction oil oxidation decomposition easily, especially diffusion pump are often working under high temperature environment, makes the vapour inside the system pressure, vacuum degree is reduced, so the vacuum pump oil has good thermal oxidation stability.
4. Good corrosion resistance and demulsibility
If the vacuum pump suction is corrosive gas, can react with oil, corrosion inside the pump parts;Inhalation of often contain water vapor condensed water in the air, vacuum pump oil emulsification and metal corrosion, so demand has good corrosion resistance and demulsibility
5. High flash point
Main requirements do not carry light component in the vacuum pump, lest affect oil saturation vapor pressure.
6. The lower limit stress
Ultimate pressure is an important use of vacuum pump oil performance indicators in the lowest limit of vacuum pressure in order to understand the limit of the rotary vane vacuum pump or rotary piston vacuum pump pressure.