Check the listing for details. MT-704 Diffusion Pump Oil - One Gallon | High Vacuum | Dow Corning Equivalent. Condition: New. Listed at 549.99 USD. 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. SPECIFICATIONMT-702MT-704MT-705Molecular DescriptionMixed phenylmethyl dimethyl cyclosiloxaneTetramethyl tetraphenyl trisiloxanePentaphenyl trimethyl trisiloxaneColorClearLight StrawClear/Light StrawUltimate Untrapped Vacuum (torr)10E-510E-7 to 10E-85 E-9Ultimate Trapped Vacuum–to 10E-11to 10E-11Extrapolated Vapor Pressure at 25 ºC1 x 10E-62.1 x 10E-85 x 10E-10Specific Gravity at 25 ºC1.071.071.09Viscocity at 25 ºC4539175Flash Point, open cup (ºC)193221243Boiling point, 0.5 torr (ºC)180215245Typical Boiler Temperature (ºC)190220260Heat of Vaporization (kcal/gm mole)21.7/190 ºC25.5/200 ºC28.2/250 ºCSurface Tension (dynes)3037.336.5Molecular Weight–484546Price per gallon$375.00$475.00$595.00