In lubricating oil

The presence of these acids in crude oils and petroleum cuts causes problems for the refiner because they form stable emulsions with caustic solutions during desalting or in lubricating oil production very corrosive at high temperatures (350-400°C), they attack ordinary carbon steel, which necessitates the use of alloy piping materials. 

Sulfated ash in lubricating oils in greases NF T 60-143 ISO 3987 ASTM D 874 NF T 60-144 ASTM D 128 Weight of residue after treatment of the ash by sulfuric acid and calcination As above... 

Burdett, R.A., L.W. Taylor and L.C. Jones Jr (1955), Determination of aromatic hydrocarbons in lubricating oil fractions by far UV absorption spectroscopy , p. 30. In Molecular Spectroscopy Report Conf. Institute of Petroleum, London. 

An example of an appHcation of hydrocracking is in lubricating oils, where it is used to improve the viscosity index, color, and color stabiHty to reduce polymer formation (storage stabiHty) and to decrease the neutralization number (acidity) (61). 

Spectrographic analysis allows accurate, rapid measurements of many of the elements present in lubricating oil. These elements are generally classified as wear metals, contaminates, or additives. Some elements can be listed in more than one of these classifications. Standard lubricating oil analysis does not attempt to determine the specific failure modes of developing machine-train problems. Therefore, additional techniques must be used as part of a comprehensive predictive maintenance program. 

A variety of chemical additives can be incorporated in lubricating oils to improve their properties under boundary lubrication conditions. Some of these additives react with the surfaces to produce an extremely thin layer of solid lubricant, which helps to separate the surfaces and prevent seizure. Others improve the resistance of the oil film to the effect of pressure. 

The entrainment of air in lubricating oil can be brought about by operating conditions (for example, churning) and by bad design such as a return pipe that is not submerged. The air bubbles naturally rise to the surface, and if they do not burst quickly, a blanket of foam will form on the oil surface. Further air escape in thus prevented and the oil becomes aerated. Oil in this condition can have an adverse affect on the system that, in extreme cases, could lead to machine failure. The function of an anti-foam additive is to assist in the burst of air bubbles when they reach the surface of the oil. 

Silicone rubber as a shaft seal and backing material has a number of special applications. It can be used over a temperature range of —60°C to 260°C (—76°F to 500°F) in air or suitable fluids. Its abrasion resistance is good with hard shafts having a 0.000254 mm RMS surface finish. Commercial grades of silicone rubber are compatible with most industrial chemicals up to 260°C (500°F). In lubricating oils, the limiting temperature is 120°C (250°F), but special types have been developed for use up to 200°C (392°F). 

Environments are either gases or liquids, and inhibition of the former is discussed in Section 17.1. In some situations it would appear that corrosion is due to the presence of a solid phase, e.g. when a metal is in contact with concrete, coal slurries, etc. but in fact the corrosive agent is the liquid phase that is always present. Inhibition of liquid systems is largely concerned with water and aqueous solutions, but this is not always so since inhibitors may be added to other liquids to prevent or reduce their corrosive effects — although even in these situations corrosion is often due to the presence of small quantities of an aggressive aqueous phase, e.g. in lubricating oils and hydraulic fluids (see Section 2.11). 

Vollmar, Petterson, and Petruzzelli27 in 1949 disclosed that the following commercial applications of comparative absorptiometry were being made in the petroleum industry sulfur in hydrocarbon mixtures, tetraethyllead fluid in gasoline, additives (such as metal soaps) in lubricating oils, and the metal content of metallo-organic derivatives. Complete documentation of subsequent developments in the petroleum industry is out of place here but it is easy to cite proof that comparative absorptiometry has been successful in that industry.27 32... 

Table 8-3. Barium, Calcium, and Zinc in Lubricating Oils ...

Ethoxylation of the base alcohol always improves the solubility of the sulfate. As an example, sodium hexadecyl ether (2 EO) sulfate gives a clear 10% solution in water at 40°C, which becomes a viscous gel at 30°C [59]. Alcohol ether sulfates are also more soluble in organic solvents than the corresponding alcohol sulfates. Sodium hexadecyl and octadecyl ether (2 EO) sulfates are soluble at 1% concentration in lubricating oil, at 2.5% in benzene and chloroform, and at 5% in tetrachloroethylene, whereas alcohol-ethoxylated sulfates with 10 mol of ethylene oxide are soluble at 5% in lubricating oil [59]. 

For use in lubrication oils Ca salts of isostearyl ether carboxylic acids are described as multifunctional additives to achieve a good water tolerance of the oil and good antiwear characteristics [182]. 

In the area of process monitoring TLC has been used for the study of the thermal decomposition of zinc di-isopropyl dithiophosphate (antiwear additive in lubricating oils) [458]. TLC analysis has been reported as a quality control tool for analysis of dispersing agents (alkylsalicylates, thioalkylphenolates), AOs (dithiophosphates, dialkyldithiophosphates) and their intermediates in lubricating oil (UV detection,... 

Reversed-phase TLC has been applied to identify antioxidants and plasticisers [394], zinc dialkyldithio-phosphates and polymer additives in lubrication oil... 

Eleven zinc dialkyldithiophosphates (ZDDPs) in lubricating oil additives were separated by NPLC [723] eight ZDDPs were separated on an ODS column... 

---