4. Summary of Test Method
4.1 The material to be tested is heated under reflux with a water-immiscible solvent, which co-distills with the water in the sample. Condensed solvent and water are continuously separated in a trap, the water settling in the graduated section of the trap and the solvent returning to the still.
5. Significance and Use
5.1 Aknowledge of the water content of petroleum products is important in the refining, purchase, sale, and transfer of products.
5.2 The amount of water as determined by this test method (to the nearest 0.05 or 0.1 volume %, depending on the trap size used) may be used to correct the volume involved in the custody transfer of petroleum products and bituminous materials.
5.3 The allowable amount of water may be specified in contracts.
6. Solvent-Carrier Liquid
6.1 A solvent-carrier liquid appropriate to the material being tested (see Table 1) shall be used.
6.1.1 Aromatic Solvent - The following aromatic solvents are acceptable:
6.1.1.1 Industrial Grade Xylene - (Warning - Flammable. Vapor harmful.)
6.1.1.2 A blend of 20 volume % industrial grade toluene and 80 volume % industrial grade xylene. (Warning - Flammable. Vapor harmful.)
6.1.1.3 Petroleum Naphtha or Coal Tar Naphtha, free of water, yielding not more than 5% distillates at 125°C (257°F) and not less than 20% at 160°C (320°F) and with a relative density (specific gravity) not lower than 0.8545 at 15.56/15.56°C (60/60°F). (Warning - Extremely flammable. Harmful if inhaled. Vapors may cause fire.)
6.1.2 Petroleum Distillate Solvent - A petroleum distillate solvent, 5% boiling between 90 and 100°C (194 and 212°F) and 90% distilling below 210°C (410°F), shall be used. Percent may be determined by mass or by volume. (Warning - Flammable. Vapor harmful.)
6.1.3 Volatile Spirits Solvent - The following volatile spirits solvents are acceptable:
6.1.3.1 Petroleum Spirit, with a boiling range from 100 to 120°C (212 to 248°F). (Warning - Flammable. Vapor harmful.)
6.1.3.2 Iso-octane, of 95% purity or better. (Warning - Extremely flammable. Harmful if inhaled. Vapors may cause fire.)
6.2 Solvent Blank - The water content of the solvent shall be determined by distilling anequivalent amount of the same solvent used for the test sample in the distillation apparatus and testing as outlined in Section 10. The blank shall be determined to the nearest scale division and used to correct the volume of water in the trap in Section 11.
