Diffusion Pump Oil Cross-Reference

Unlike the Turbomolecular Pump the Diffusion Pump recquires a working fluid to move gas molecules. This fluid is commonly reffered to as an oil, due to the fluids resembling oils in feel and consitency. Below is a list of various Diffusion Pump Oils and their physical properties.

Dow Corning

Silicone Oils

Physical Properties

Name	Vapor Pressure	Viscosity 25°C	Boiling Point 0.5 torr	Flashpoint	Condensation Point	Density
DC 702	1 x 10⁻⁶ Torr	45 mm²/s	180°C	≥ 193°C	°C	1070 kg/m³
DC 704	2 x 10⁻⁸ Torr	39 mm²/s	215°C	221°C	°C	1070 kg/m³
DC 705	3 x 10⁻¹⁰ Torr	175 mm²/s	245°C	243°C	°C	1090 kg/m³

Kurk J. Lekser Corporation

Silicone Oils

Physical Properties

Name	Vapor Pressure	Viscosity 25°C	Boiling Point 0.06 torr	Flashpoint	Condensation Point	Density
KJLC 704	8.4 x 10⁻⁸ Torr	46 mm²/s	223°C	220°C	°C	1100 kg/m³
KJLC 704-T	8.4 x 10⁻⁸ Torr	37 mm²/s	210°C	220°C	°C	1070 kg/m³
KJLC 705	3 x 10⁻¹⁰ Torr	165-185 mm²/s	245°C	243°C	°C	1090 kg/m³

VacOil

Silicone Oils

Physical Properties

Name	Vapor Pressure	Viscosity 25°C	Flashpoint	Condensation Point	Density
DP Grade 704	6.65 x 10⁻⁸ Torr	36 mm²/s ± 4 mm²/s	≥ 210°C	≥ -35°C	1050 ∼ 1080 kg/m³

Leybold

Hydrocarbon Oils

Physical Properties

Name	Vapor Pressure	Viscosity 25°C	Boiling Point 0.06 torr	Flashpoint	Condensation Point	Density
Diffilen Leicht		mm²/s	°C	°C	°C	kg/m³
Diffilen		mm²/s	°C	°C	°C	kg/m³
Diffilen Extra		mm²/s	°C	°C	°C	kg/m³
Diffilen Ultra		mm²/s	°C	°C	°C	kg/m³
LVO 500	4 · 10⁻⁹ mBar	mm²/s	°C	> 250 °C	°C	868 kg/m³
LVO 521	6 · 10⁻⁶ mBar	mm²/s	°C	196 °C	°C	885 kg/m³

Silicone Oils

Physical Properties

Name	Vapor Pressure	Viscosity 25°C	Boiling Point 0.06 torr	Flashpoint	Condensation Point	Density
LVO 521	3 · 10⁻¹⁰ mBar	mm²/s	°C	240 °C	°C	1095 kg/m³

Polyphenyl Ether Oils

Santovac

Physical Properties

Name	Vapor Pressure	Viscosity 38°C	Viscosity 90°C	Viscosity 260°C	Boilding Point 0.5 Torr	Flashpoint	Condensation Point	Density
Santovac 5	4 x 10⁻¹⁰ Torr	363 mm²/s	13.1 mm²/s	1.2 mm²/s	275 °C	288°C		1198 kg/m³