MTS Offers 702, 704 & 705 Pump Oil & Dow Corning High Vacuum Grease
This listing is for our MT-704 diffusion pump oil.
Dow Corning no longer offers DC-702, DC-704, and DC-705 for sale to the
general market. Midwest Tungsten has filled the gap by offering private label
702, 704, and 705 chemically equivalent products in gallon containers and 500
cc bottles. Our MT-702, MT-704, and MT-705 are all in stock for immediate
delivery.
MT-704 diffusion pump fluid is a single component fluid for high vacuums of
10E-6 to 10E-8 torr, untrapped or 10E-10 to 10E-11, trapped. It performs well
in tough, rugged applications and offers quick pumpdown, even after exposure to
air at operating temperatures, although this is not recommended. Replacement
for and equivalent to Dow Corning DC-704. Sold as DS-704 and Invoil 704
elsewhere.
MT-702 and MT-705 are available in separate listings.
SPECIFICATION MT-702 MT-704 MT-705
Molecular Description Mixed phenylmethyl dimethyl cyclosiloxane Tetramethyl
tetraphenyl trisiloxane Pentaphenyl trimethyl trisiloxane
Color Clear Light Straw Clear/Light Straw
Ultimate Untrapped Vacuum (torr) 10E-5 10E-7 to 10E-8 5 E-9
Ultimate Trapped Vacuum – to 10E-11 to 10E-11
Extrapolated Vapor Pressure at 25 ºC 1 x 10E-6 2.1 x 10E-8 5 x 10E-10
Specific Gravity at 25 ºC 1.07 1.07 1.09
Viscocity at 25 ºC 45 39 175
Flash Point, open cup (ºC) 193 221 243
Boiling point, 0.5 torr (ºC) 180 215 245
Typical Boiler Temperature (ºC) 190 220 260
Heat of Vaporization (kcal/gm mole) 21.7/190 ºC 25.5/200 ºC 28.2/250 ºC
Surface Tension (dynes) 30 37.3 36.5
Molecular Weight – 484 546
Price per gallon $375.00 $475.00 $595.00