ASTM D95 Standard Test Method for Water in Petroleum Products and Bituminous Materials by Distillation

The standard "ASTM D95 Standard Test Method for Water in Petroleum Products and Bituminous Materials by Distillation," developed by the American Society for Testing and Materials (ASTM), describes a test method for determining the water content of petroleum products, tars, and other bituminous materials in the range of 0 to 25 percent by volume by distillation. Volatile water-soluble material, if present, can be measured as water. Specific products considered during the development of this test method are listed in the table provided within the standard. The test methods described in ASTM D244 for bituminous emulsions and in ASTM D4006 for crude oils are applicable. For some oil types, satisfactory results from ASTM D1796 can be obtained.

For the purposes of this standard, bituminous material is defined in petroleum technology as a black or dark-coloured, very viscous liquid or semi-solid material consisting essentially of high molecular weight condensed aromatic or naphthenic compounds or both.

The material to be tested is heated under reflux with a water-immiscible solvent that is distilled along with the water in the sample. The condensed solvent and water are continuously separated in a trap, with the water precipitating in the graduated section of the trap and the solvent returning to the distiller.

Knowing the water content is critical for the refining, purchasing, selling, and transfer of petroleum products because it can impact water quality and volume calculations. The water content determined by this test method (to the nearest 0,05 or 0,1 percent by volume, depending on the trap size used) can be used to correct the volume involved in the containment transfer of petroleum products and bituminous materials. The allowable water content can be specified in contracts.

The method described measures water content in the range of 0 to 25 percent by volume in petroleum products (e.g., fuels, oils), tars, and bituminous materials. This method is applicable to the specific products listed in the standard.

In the test, a sample is heated with a solvent carrier liquid (e.g., toluene or xylene) in a distillation apparatus. The water is separated and collected in a graduated trap, where its volume is measured. This method accounts for volatile water-soluble substances that can be measured as water. The equipment used includes a distillation flask, a condenser, and a graduated trap to collect the water. This equipment must meet the specifications described in ASTM E123.

The ASTM D95 standard is required in the petroleum and bituminous materials industries for these critical reasons:

• Accurate volume measurement for surveillance transfer: Knowing the water content in petroleum products is crucial for refining, purchasing, selling, and transferring these materials. The ASTM D95 test method determines water content by volume based on the trap size used, allowing for precise volume corrections during surveillance transfer. This ensures fair transactions by accounting for water that may dilute the product.
• Quality control and contract compliance: This standard helps verify that petroleum products and bituminous materials meet contract specifications, which typically include allowable water content limits. Excess water can affect product quality, performance, and value. Therefore, compliance with these limits is critical for both suppliers and buyers.
• Operational efficiency in refining: Knowledge of water content is vital during refining processes. Excessive water can cause problems such as corrosion, emulsion formation, or inefficiency in processing equipment. Refiners can monitor and control water content using the ASTM D95 standard, optimizing operations and preventing equipment damage.
• Safety and performance: Water in petroleum products or bituminous materials can pose safety hazards, such as foaming or pressure buildup during processing, or performance issues in applications such as asphalt or fuel oils. The standard minimizes these risks by providing a reliable method for measuring water content.
• Standardized testing for consistency: This standard provides a globally recognized, standardized distillation method for measuring water content in products such as petroleum, tar, and bituminous materials. This consistency promotes confidence and reliability in test results by ensuring comparable results across laboratories and industries.
• Regulatory and environmental compliance: Accurate water content data helps meet regulatory requirements for product quality and environmental standards. For example, excessive water in fuels can lead to incomplete combustion, increase emissions, and violate environmental regulations.

This standard is critical because it promotes fair trade, ensures product quality, enhances operational safety, and maintains consistency in testing—all of which are vital to the petroleum and bituminous materials industries.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, boasts a strong team of employees who closely follow global developments in science and technology and are constantly improving themselves. In this context, we also provide testing services in accordance with the "ASTM D95 Standard Test Method for Water in Petroleum Products and Bituminous Materials by Distillation."