WATER SOLUBILITY IN HYDROCARBONS AND ALIPHATIC ESTER LUBRICANTS: D4056
EXPLANATION
This test method covers a procedure for estimating the equilibrium solubility of water and its vapor in hydrocarbon and aliphatic ester lubricants, at temperatures between 277 and 373 K. This test method is limited to liquids of low to moderate polarity and hydrogen bonding, with predicted solubilities not over 1000 ppm by weight in hydrocarbons, or 30 000 ppm by weight in oxygenated compounds, at 298 K. Olefins, nitriles, nitro compounds, and alcohols are specifically excluded. This test method is recommended only for liquids not containing widely different chemical species; for example, blends of esters with hydrocarbons, and lubricants containing detergents, dispersants, rust preventives, or load carrying additives are excluded.
TEST SUMMARY
The solubility is calculated from data for density, refractive index, and molecular weight of a hydrocarbon. For an ester, saponification number is also required.
TEST PRECISION
The precision of this test method is entirely dependent on that of the test methods used to measure the four components that go into the calculations.
