The method utilizes co-distillation (often referred to as the Dean-Stark method). The sample is heated under reflux conditions with a water-immiscible solvent. As the solvent boils, it vaporizes and carries the water moisture from the sample along with it.
The volume of the separated water is measured directly from the graduations on the trap and expressed as a percentage of the original sample volume. Apparatus and Safety
The standard specifies a specialized distillation apparatus consisting of: A glass or metal vessel (usually 500 mL to 2000 mL). Heater: Typically an electric heating mantle or gas burner.
ASTM D95 Water Content | PDF | Petroleum | Distillation - Scribd Astm D95 Pdf
A glass receiver (usually 2 mL to 25 mL capacity) to collect and measure the water. 4. Solvent Selection The choice of solvent depends on the material being tested: Material to be Tested Recommended Solvent Asphalt, Bitumen, Tar Aromatic (Xylene/Toluene blend) Fuel Oil, Lubricating Oil Petroleum Distillate Volatile Spirits 5. Calculation and Accuracy
Following the exact sequence ensures repeatable and reproducible results. Step 1: Sample Preparation Thoroughly mix the laboratory sample to ensure homogeneity.
is a critical international standard used to determine the water content in petroleum products, tars, and other bituminous materials . Developed by ASTM International, this test method utilizes distillation to accurately measure the volume of water present in a given sample. Accurate determination of water content is essential for ensuring product quality, meeting regulatory compliance, and protecting industrial equipment from corrosion and damage. 1. Scope and Significance of ASTM D95 The method utilizes co-distillation (often referred to as
The percentage of water is calculated based on whether the sample was measured by volume or by mass. Calculation by Volume
Water in lubricating oils accelerates oxidation, degrades additives, and leads to component rust. Monitoring water content prevents catastrophic mechanical failures in turbines, engines, and gearboxes. Fiscal Custody Transfer
: The vapors rise into a reflux condenser, where they are cooled and liquefied. Separation The volume of the separated water is measured
The most widely used solvent for general petroleum products. Toluene: Used frequently for lubricants and fuels.
As the mixture is heated, the water in the sample co-distills with the solvent.
