Consists of esters or specially selected hydrocarbon fractions. They were developed for vapor-diffusion pump fluids:
- High purity, very low pressure, very stable
- Pressures lower than 10-7 torr obtainable
- No need for cold trap
- Good pumping speed
- No corrosive deposits or vapors
Physical Properties of Apiezon Oils
| |
Type BW |
| Vapor Pressure,vtorr @20°C |
10-6 |
| Boiling Point,°C @ 1 torr |
225 |
| Flash Point (open cup)°F |
480 |
| Pour Point(ASTM) °F |
10 |
| Density, g/ml @ 20°C |
0.882 |
| @ 40°C |
0.869 |
| Viscosity, kinematic,cS @ 20°C |
361 |
| @ 50°C |
98.1 |
| @ 100°C |
10.1 |
| Coefficient of Expansion per °C over 20-30°C (ASTM) |
0.00070 |
| Thermal Conductivity Btu/in |
0.89 |
Invoil Oil BW
A water-white oil with a higher pumping speed than oil B, although all other characteristics are similiar to B. Because it has an extremely high purity it is suitable for use in the evacuation of mass spectrometers.