Lubricant, vacuum

Bearings and sealing Ball bearings especially for high speed high stiffness applications No or low lubrication (vacuum pumps, dental drill handpieces) Under corrosive conditions (food ndustry chemistry metallurgy) high and low temperatures... 

PPG-24 butyl ether PPG-33 butyl ether PPG-40 butyl ether PPG-53 butyl ether lubricant, unsat. polyesters Aluminum stearate lubricant, vacuum pumps PerfI uoropolyether lubricant, varnishes Cl 8 acid triglyceride lubricant, veterinary PEG-35 castor oil... 

The disadvantage involved in using these fresh-oil-lubricated vacuum pumps was the provision of fresh-oil logistics and waste oil disposal, which was cumbersome when operating many such vacuum pumps constantly. 

When oil-lubricated rotary vane vacuum pumps are used in connection with a chemistry application, then usually fresh-oil-lubricated vacuum pumps will be chosen. The oil which in all rotary vane vacuum pumps serves the purpose of inner sealing and lubrication is constantly fed into the pump chamber and thus passes together with the gas, respectively vapour flow through the pump. 

The oil quantities within the pump chamber are relatively small, since the use of too much oil is prohibitive in view of the then occurring waste oil quantities. Because of the thus unavoidably restricted possibility of dissipating the compression heat, the active pumping section is cooled by means of a double water jacket. Fresh-oil-lubricated vacuum pumps which are intended for deployment in chemical production lines are manufactured with pumping speeds ranging from 50 to approximately 700 m h . The ultimate pressure attainable by these two-stage pumps reaches values down to 0.5 mbar (abs.)... 

Textile lubricants (fiber and machine lubricants) Two-cycle engine lubricants Vacuum pump lubricants... 

Antiseize compounds (vacuum technology) Material applied to a surface to prevent cold welding and galling. Example Silver-plated stainless steel bolts. See also Lubricant, vacuum. 

Lubricant (vacuum technology) A lubricating liquid or solid material that is vacuum-compatible. Examples M0S2 dry lubricant silicone greases. Note Graphite is not vacuum-compatible as a lubricant. 

Solid lubricant (vacuum technology) A non-Uquid material that provides lubrication and does not creep away from the point of application in the way that a liquid lubricant does. 

Details are given in Table 3.3. As with all correlations, one should beware of using them if thp mea su ments taken are outside the region of the correlation that estabTishedthem. This method is commonly called ndM and is used mainly with vacuum distillates and lubricating oils. 

Ultra-high vacuum (UHV) surface science methods allow preparation and characterization of perfectly clean, well ordered surfaces of single crystalline materials. By preparing pairs of such surfaces it is possible to fonn interfaces under highly controlled conditions. Furthennore, thin films of adsorbed species can be produced and characterized using a wide variety of methods. Surface science methods have been coupled with UHV measurements of macroscopic friction forces. Such measurements have demonstrated that adsorbate film thicknesses of a few monolayers are sufficient to lubricate metal surfaces [12, 181. 

McFadden C F and Geiiman A J 1995 Ultra-high vacuum boundary lubrication of the Cu-Cu interface by 2,2,2-trifluoroethanol Langmuir 273-80... 

Some simple apparatus, suitable for high vacuum distillation, are collected in Figs. 11, 26, 1-4. Fig. 11, 26, 1 represents an apparatus, which is particularly well adapted for solids the ground glass joint must be lubricated with a grease of negligible vapour pressure. Hickman s vacuum still is shown in Fig. 11, 26, 2 it is about 60 mm. in diameter. 

Du Pont called this new lubricant material Krytox (64,65) and initially it had such extraordinary properties that it sold for 200/kg ( 187kg ca 1993). Krytox was and is used ia most of the vacuum pumps and diffusion oil pumps for the microelectronics iadustry ia this country and ia Japan because it produces no hydrocarbon (or fluorocarbon) vapor contamination. It has also found important appHcations ia the lubrication of computer tapes and ia other data processiag appHcations as weU as military and space appHcations. 

Halogenated hydrocarbons that are inexpensive sometimes are used alone or in blends with phosphate esters as fire-resistant hydrauHc fluids. Other halogenated fluids are used for oxygen-compressor lubricants, lubricants for vacuum pumps that are in contact with corrosive materials, solvent-resistant lubricants, and other lubricant appHcations where highly corrosive or reactive materials are being handled. 

As is indicated in Figure 4, saturates contribute less to the vacuum gas oil (VGO) than the aromatics, but more than the polars present at percentage, rather than trace, levels. VGO itself is occasionally used as a heating oil but most commonly it is processed by catalytic cracking to produce naphtha or by extraction to yield lubricant oils. 

Vacuum Distillation. Vacuum distUlation evolved as the need arose to separate the less volatile products, such as lubricating oUs, from petroleum without subjecting these higher boiling materials to cracking conditions. The boiling point of the heaviest cut obtainable at atmospheric pressure (101.3 kPa = 760 mm Hg) is limited by the temperature (ca 350°C) at which the residue starts to decompose or crack. It is at this point that distUlation in a vacuum pipe stUl is initiated. 

The early developments of solvent processing were concerned with the lubricating oil end of the cmde. Solvent extraction processes are appHed to many usefiil separations in the purification of gasoline, kerosene, diesel fuel, and other oils. In addition, solvent extraction can replace fractionation in many separation processes in the refinery. For example, propane deasphalting (Fig. 7) has replaced, to some extent, vacuum distillation as a means of removing asphalt from reduced cmde oils. 

Considering their heat sensitivity, the separation of fatty acids and rosin with minimal degradation by fractional distillation under vacuum and/or in the presence of steam is surprisingly good (3). Tad od rosin (TOR) contains about 2% fatty acid and smad amounts of neutrals. Tad od fatty acid (TOFA) contains as Htde as 1.2% rosin and 1.7% neutrals. In typical U.S. TOFA, 49% of the fatty acids is oleic, 45% linoleic, and 3% palmitic, stearic, and eicosatrienoic acid. TOR and TOFA are upgraded to resins and chemicals for the manufacture of inks (qv), adhesives (qv), coatings (qv), and lubricants (see Lubrication AND lubricants). 

Lubricants. TeUurides of titanium, 2irconium, molybdenum, tungsten, and other refractory metals are heat- and vacuum-stable. This property makes them useful in soUd self-lubricating composites in the electronics, instmmentation, and aerospace fields (see Lubrication and lubricants). Organic teUurides are antioxidants in lubricating oUs and greases. 

Reaction of TYZOR TPT with polyperfluoroalkylene ethers containing a carbonyl group produces a complex that is an excellent surface-treating agent, imparting improved surface wettabiUty and anticorrosion properties to metal surfaces (144). These complexes can be used by themselves, or as additives to perfluoropolyethers as vacuum pump oils, lubricant oils, or mold release agents. 

Barium improves the performance of lead ahoy grids of acid batteries (see Batteries) (34). In the form of thin films, barium has been found to be a good high temperature lubricant on the rotors of anodes operating at 3500 rpm ia vacuum x-ray tubes (35). 

Fuels, Lubricants, and Transmission Fluids. Polyol esters of neopentanoic acid have been used as high vacuum pumping hquids that are stable in chemically aggressive environments (70). Esters such as 6- -ani1inophenoxy)hexy1 pivalate are used as antioxidants for synthetic ester lubricants (71). PivaUc anhydride [1538-75-6] has been claimed as an antiknock additive for gasoline (72). 

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