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Diffusion Pump Oil RUI704-oil for diffusion pump

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1. 704 silicone diffusion pump oil/704 diffusion pump oil

2. Diffusion pump oil 704

3. Oil for diffusion pumps

4. Vacuum diffusion pump oil 

Chemical Component: Tetramethyl tetraphenyl trisiloxane

Cas No: 3982-82-9

Chemical structure:

Diffusion Pump Oil RUI704 is a colorless transparent oily, single-component fluid designed for high vacuum of 10-7torr (untrapped). It performs well in tough, rugged applications and offers quick pump down, even after exposure to air at operating temperatures. RUI704 is thermally and chemically stable allowing it to keep pump jets free of tars and hard carbon. So frequent Diffusion Pump Oil Change is not necessary for RUI diffuison pump oil. 

Since Dow Corning stopped the supplying of the silicone diffusion pump oils into the general market, RUI704 has been taken as an ideal replacement of Dow Corning 704 diffusion pump oils. 

Technical Index



Chemical composition

Tetramethyl tetraphenyl trisiloxane

Ultimate Vacuum, torr



Saturated Vapor Pressure, torr


Specific Gravity

1.06 ~ 1.07

Viscosity (25°C), cSt


Flash Point °C


Refractive Index 25°C


Congealing Point °C


Molecular Description


GC-MS and IR test reports for every batch of Diffusion Pump Oil RUI704 is available from RUIchem silicones, if you need it, please send email to


RUI704 can be used in variety of applications, including:

Electrical and electronics industry

TV tubes, fluorescent tubes, cathode ray tubes

ordinary bulbs


rectifier metallised film vacuum system

Optical industry

surface improvements

anti reflective coatings

optical filters and mirrors

Metallurgy industry

high-vacuum furnaces

melting, degassing and sintering refractory metals; thick-film deposition

Plastics industry

surface improvements

mirror coatings

protective coatings

film coatings

Other industries

processing metals and fuels


molecular plants

R & D plants

mass spectrometry


Be used as transmission fluid in high-temperature carriers and various instruments.

Package, Transportation & Storage

Diffusion Pump Oil RUI704 is available in 1kg plastic bottles, 1gallon plastic drums, 5kg plastic drums, 25kg plastic drums, 25kg Iron drums or 200kg Iron drums.

Transport as non-hazardous chemicals, keeping away from rain and sunlight.

Shelf life: 3 years.