This test method is used as an indication of water and sediment in middle distillate fuels such as Grade Nos. 1 and 2 fuel oil (Specification D 396), Nos. 1-D and 2-D diesel fuel (Specification D 975), and Nos. 0-GT, 1-GT, and 2-GT gas turbine fuels (Specification D 2880).

Appreciable amounts of water and sediment in a fuel oil tend to cause fouling of the fuel-handling facilities and to give trouble in the fuel system of a burner or engine. An accumulation of sediment in storage tanks and on filter screens can obstruct the flow of oil from the tank to the combustor. Water in middle distillate fuels can cause corrosion of tanks and equipment, and if detergent is present, the water can cause emulsions or a hazy appearance. Water is necessary to support microbiological growth at fuel water-interfaces in fuel systems.

1.1 This test method covers the determination of the volume of free water and sediment in middle distillate fuels having viscosities at 40°C (104°F) in the range of 1.0 to 4.1 mm²/s (1.0 to 4.1 cSt) and densities in the range of 770 to 900 kg/m³.

Note 1—Fuels corresponding to Specification D 975 Grades 1D and 2D, Specification D 2880 Grades 0-GT, 1-GT and 2-GT, and Specification D 3699 Grades 1-K and 2-K will usually fall in this viscosity and density range. Test Method D 1796 is intended for higher viscosity fuel oils.

1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.3 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.