 | ||||||||||||||||||||
| ||||||||||||||||||||
 | ||||||||||||||||||||
|
Base Oil Lubricating Properties Table of Contents Physical & Chemical Properties Paraffins are relatively unreactive and thus have better oxidation stability compared to naphthenes. Thus, they can be used longer at higher temperatures. For example, oil companies state that turbine oils are blended using the best paraffinic base stocks. However, because of the relative stability and other properties of paraffin's, they have poor solvency for additives. For example, elemental sulfur has limited solubility in paraffinic base oils and higher solubility in naphthenic base oils. Conversely, naphthenics have good solvency for many additives. Aniline point is a measure of the solvent power of oil. It is an indication of the solvent effect of oil on other organic compounds such as rubber, seals, gaskets, and electrical insulation. Aniline point is defined as the lowest temperature at which oil is completely miscible, that is clear, with an equal volume of aniline. The lower the temperature, the greater the solvency and the more likely rubber and polymeric compounds will swell. Commercial "handy" oil has an aniline point of 90 degree C indicating it would cause more rubber swell than a paper machine oil with an aniline point of approximately 120 degree C. Aniline point is measured by ASTM D 611 where a sample of oil is introduced into a vial containing an equal portion of aniline. The fluids are warmed and lightly mixed until they are completely soluble, then allowed to cool. The temperature at which a haze appears, indicating the two liquids are no longer soluble, is considered to be the aniline point. In addition, naphthenic oils dissolve greater quantities of gases than do paraffinics. Also, paraffins have slightly higher flash points than naphthenics. Because of their wax content, paraffins have higher pour points than naphthenics. For example, for two oils of the same viscosity at 40 degree C, the paraffinic would have a pour point of -18 degree C and the naphthenic a pour point of - 43 degree C. In general, paraffins have a higher viscosity index than naphthenics. For example, 100 and 70 VI respectively. The VI of turbine oils range from 96 for a low viscosity oil to 102 for a high viscosity oil. In contrast, general utility oil has a low VI of 29 to 60. Paraffins generally have a lighter color than naphthenics. Pressure viscosity coefficients for paraffinic and naphthenic oils are similar, even though the naphthenic base oils are more affected by pressure than the paraffinics. The range for naphthenics is 1.3 to 2.8 X 10-8 m2 N-1, and 1.4 to 3.4 X 10-8 m2 N-1 for the paraffinics depending upon viscosity (Reference 1). Pure base oils are not suitable lubricants for industrial use because of their poor lubricating and stability properties. With oxidation and corrosion inhibitors they are suitable lubricants only under pure hydrodynamic lubrication. They are sold primarily to companies that blend their own additives into the base oils. For more information call 1-888-HERGUTH (437-4884) | |||||||||||||||||||
 |
| NEWS AND EVENTS |
| INVESTIGATE FURTHER |
| Case Studies White Papers Example Reports Glossary |
| FORMS |
| Client Forms Equipment Forms Sample Forms |
 |
 |