ASTM D6422 Standard Test Method for Water Tolerance (Phase Separation) of Gasoline-Alcohol Blends
1. Scope
1.1 This test method covers the ability of gasoline-alcohol blends to retain water in solution or in a stable suspension at the lowest temperature to which they are likely to be stored or exposed in use.
1.2 This test method is intended to measure the temperature at which a gasoline-alcohol blend separates into two distinct phases in accordance with the criteria defined in this test method. Samples that form a haze are considered not to have phase separated.
1.3 This test method is applicable to gasoline-alcohol blends for use as fuels in spark-ignition engines that contain saturated C1 to C4 alcohols only. The test method does not apply to fuels that contain an alcohol as the primary component, such as M85 or Ed85, or to gasoline-ether blends.
1.4 The values stated in SI units are the standard, except when other units are specified by federal regulation. Values given in parenthesis are provided for informational purposes.
1.5 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of the standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D2500 Test Method for Cloud Point of Petroleum Products
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4306 Practice for Aviation Fuel Sample Containers for Tests Affected by Trace Contamination
D4814 Specification forAutomotive Spark-Ignition Engine Fuel
D5842 Practice for Sampling and Handling of Fuels for Volatility Measurement
E 1 Specification for ASTM Thermometers
3. Terminology
3.1 Definitions:
3.1.1 gasoline, n - a volatile mixture of liquid hydrocarbons, generally containing small amounts of additives, suitable for use as a fuel in spark-ignition, internal combustion engines.
3.1.2 gasoline-alcohol blend, n - a fuel consisting primarily of gasoline, along with a substantial amount (more than 0.35 mass % oxygen or more than 0.15 mass % oxygen if methanol is the only oxygenate) of one or more alcohols.
3.1.3 phase separation, n - the formation of two layers, a lower aqueous constituent and an upper hydrocarbon constituent, separated by either a common boundary or a layer of emulsion.
3.1.3.1 Discussion - Test specimens having droplets clinging to the sides of the container or collected on its bottom, that are visible to the unaided eye, are considered to be phase separated.
