ASTM D4625 Method for Middle Distillate Fuel Storage Stability at 43°C (110°F)
1. Scope
1.1 This test method covers a method for evaluating the inherent storage stability of distillate fuels having flash points above 38°C (100°F), by Test Methods D93, and 90 % distilled points below 340°C (644°F), by Test Method D86.
NOTE 1 - ASTM specification fuels falling within the scope of this test method are Specification D396, Grade Nos. 1 and 2; Specification D975, Grades 1-D and 2-D; and Specification D2880, Grades 1-GT and 2-GT.
1.2 This test method is not suitable for quality control testing but, rather it is intended for research use to shorten storage time relative to that required at ambient storage temperatures.
1.3 Appendix X1 presents additional information about storage stability and the correlation of Test Method D4625 results with sediment formation in actual field storage.
1.4 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 this 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:
D86 Test Method for Distillation of Petroleum Products at Atmospheric Pressure
D93 Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
D381 Test Method for Gum Content in Fuels by Jet Evaporation
D396 Specification for Fuel Oils
D975 Specification for Diesel Fuel Oils
D1193 Specification for Reagent Water
D2880 Specification for Gas Turbine Fuel Oils
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 adherent insolubles, n - gums formed during storage that remain tightly attached to the walls of the vessel.
3.1.2 filterable insolubles, n - solids formed during storage that can be removed from the fuel by filtration.
3.1.3 inherent storage stability, n - of middle distillate fuel - the resistance to change in storage in contact with air, but in the absence of other environmental factors such as water, or reactive metallic surfaces and dirt.
3.1.4 total insolubles, n - sum of the filterable insolubles plus the adherent insolubles.
