The TMC-704 Diffusion Pump Fluid from TMC Industries, supplied by Econtrol Devices, is a silicone diffusion pump oil designed for professional applications requiring deep vacuum performance. TMC-704 is chemically equivalent to Dow Corning® DC-704 and is a single-component, tetramethyl tetraphenyl trisiloxane clear fluid developed for achieving deep vacuum levels of 10⁻⁶ Torr (untrapped) and 10⁻⁸ Torr (trapped). It is widely used by aerospace, optical coating, glass, and vacuum heat-treating companies for demanding industrial processes.
TMC-704 performs effectively in rugged operating conditions with quick pump-down, even after exposure to air at high temperatures. The fluid is thermally and chemically stable, helping keep pump jets free from tars and hard carbon during operation. Due to its dielectric properties, it is also used as a reliability test fluid for high-temperature applications above 400°F, including liquid-to-liquid thermal shock testing and as a fill fluid for chemical process control instruments.
Key Features
TMC-704 Diffusion Pump Fluid offers several performance characteristics that make it suitable for professional vacuum applications, including:
Superior oxidation, heat, and chemical resistance.
Does not crack under heat or when exposed to intake gas, unlike petroleum and fatty acid ester pump oils.
Does not emit oxidation gas.
Does not produce acid, tar, pitch, or other substances when the vacuum is broken during heating.
Enables prolonged and stable operation of vacuum pumps.
Applications
TMC-704 is designed for use in:
High-vacuum oil diffusion pumps.
Aerospace applications.
Optical coating operations.
Glass manufacturing.
Vacuum heat-treating companies.
High-temperature reliability testing.
Chemical process control instruments.
Physical Properties
TMC-704 Diffusion Pump Fluid is supplied as a colorless, odorless liquid with the following physical properties:
Boiling Point: 211°C
Viscosity: 37 cSt
Specific Gravity: 1.065 g/mL
Molecular Weight: 484 g/mol
Refractive Index: 1.555
Surface Tension: 33.9 mN/m
Flash Point: 210°C
These values are measured at 25°C, unless otherwise specified.
Packaging Options
TMC Industries offers TMC-704 in multiple packaging sizes to suit different operational requirements:
1 Gallon Jug – 8.9 lb / 4 kg
5 Gallon Pail – 44 lb / 20 kg
55 Gallon Drum – 440 lb / 200 kg
Sample – 2.2 lb / 1 kg
275 Gallon Tote – Available Upon Request.
Shelf Life and Storage
When stored in its original packaging under normal storage conditions, TMC-704 has a shelf life of five years from the date of manufacture. TMC Industries also offers re-certification of the material every five years for up to twenty years.
Disposal and Recycling
This fluid can be recycled and reused. TMC Industries provides a used fluid reclamation service that restores used fluids to like-new condition. Reclaimed fluids are tested to meet new product specifications, supplied clear and odorless, and accompanied by a Certificate of Analysis. TMC Industries also offers a 100% satisfaction guarantee on reclaimed fluids.
