Lubricant viscosity

In the propane process, part of the propane diluent is allowed to evaporate by reducing pressure so as to chill the slurry to the desired filtration temperature, and rotary pressure filters are employed. Complex dewaxing requires no refrigeration, but depends on the formation of a soHd urea—/ -paraffin complex which is separated by filtration and then decomposed. This process is used to make low viscosity lubricants which must remain fluid at low temperatures (refrigeration, transformer, and hydraulic oils) (28). 

Grease Manufacture - Selected lube oil fractions arc blended with various metallic soaps to produce high viscosity lubricating greases. 

Another important set of performance specifications is produced by the European Vehicle Manufacturers Association, known by its initials CCMC. The CCMC rating G-1 corresponds roughly to API SE, and G-2 to API SF. G-3 (comparable to M1L-L-46152B, for petrol engines only) covers fuel-efficient and light-viscosity lubricants... 

As a major branch of nanotribology. Thin Film Lubrication (TFL) has drawn great concerns. The lubricant him of TFL, which exists in ultra precision instruments or machines, usually ranges from a few to tens of nanometres thick under the condition of point or line contacts with heavy load, high temperature, low speed, and low viscosity lubricant. One of the problems of TFL study is to measure the him thickness quickly and accurately. The optical method for measuring the lubricant him thickness has been widely used for many years. Goher and Cameron [3] successfully used the technique of interferometry to measure elastohydrody-namic lubrication him in the range from 100 nm to 1 /rm in 1967. Now the optical interference method and Frustrated Total Reflection (FTR) technique can measure the him thickness of nm order. 

Similarly, the use of ultra-low viscosity lubricants in compressors for refrigerators and freezers can cut energy consumption by 10%. With refrigerators, freezers and air-conditioning units representing somewhere between 5 and 10% of the UK s total electricity consumption, this is a very interesting commercial opportimity. ... 

High-viscosity lubricating oil bright stock can enhance combustion chamber deposits... 

In order to increase the yields of good quality, high viscosity lubricating oils which were in demand at that time, the industry was faced with the problem of developing more efficient methods for separating the oil from the asphaltic materials in the residue. In many cases the residue represented a substantial proportion of the crude oil. Investigations undertaken included chemical treatment with sulfuric acid (35), removal of the asphaltic materials with metallic chlorides (50, 66), and adsorption on clay (56). Solvent precipitation of the asphalts also was studied (11,18, 19, 38, 78). 

Bright stock refined, high-viscosity lubricating oils usually made from residual stocks by processes such as a combination of acid treatment or solvent extraction with dewaxing or clay finishing. 

Table 7.5 Results of analysis of effects of low viscosity lubricating oil (Conostan 20) spiked with and without enhancing agents for the analysis of 0.5 (igmC1 of each metal against standard calibration curves, similar to Figure 7.13. All analyses were carried out using scandium as internal standard. Nl, no increase in signal...

A similar list of samples was prepared for high viscosity lubricating oil (Conostan 75), as shown in Table 7.6. 

Coupling fluids are low-viscosity lubricants with high oxidative stability. Low-viscosity gear oils and engine oils may also be used for simple transmissions. 

A3/B3 for high-performance petrol and diesel light vehicle engines and/or for extended drain intervals where specified by the engine manufacturer and/or for year-round use of low-viscosity lubricants, and/or for severe operating conditions as defined by the engine manufacturer. 

A6/B6 for use at extended drain intervals in high-performance petrol and diesel light vehicle engines designed for low-friction, low-viscosity lubricants with a high-temperature/high-shear rate viscosity of 2.9-3.5 mPa.s. 

Cl - with either diesel particulate filters, DPF, or petrol three-way catalysts, TWC, requiring low-friction, low-viscosity lubricants with HTHS minimum of 2.9 mPa.s. These lubricants will increase DPF and TWC life and maintain fuel economy. These lubricants have the lowest sulphated ash/phosphorus/sulphur (SAPS) limits. 

Further contaminants detected in the sediment core could not be definitely attributed to individual emission sources, because the knowledge about their environmental occurrence and behaviour is very limited. Examples include the high-viscosity lubricant bis(-4-octylphenyl)amine (Vanlube 81 ), 3,6-dichlorocarbazole and limonene. The quantification of limonene revealed a very uniform concentration profile, which cannot be attributed to any other contamination history discussed so far. In contrast, the occurrence of 3,6-dichlorocarbazole, formerly not described as an environmental contaminant, exhibits high similarities to more modem sewage marker compounds (see Tab. 2). 

Figure 15-20. Dependence of transition temperature on viscosity lubricant, rubbing speed and load. From data by R. S. Fein [49].

The undistilled residue in the crude still can be made to yield a high-viscosity lubricant, used mostly in heavy-duty gear oils, by treating it with liquid propane under pressure to precipitate resins and asphalt and then putting the material recovered from the propane solution... 

TABLE 16-8. PROPERTIES OF REFINERY-RUN MEDIUM-VISCOSITY LUBRICANT STOCKS... 

ROLE VISCOSITY LUBRICATION PROC ASME SYMP NEW YORK 1958... 

Figure 4.31 Stress vs. strain at various temperatures for DuPont Crastin S600F10 NC010— medium viscosity, lubricated PBT resin [4].

In the case of noncompatibilized blends, the chain ends and low-molecular-weight additives migrate to the interphase, providing a low-viscosity lubricating... 

---