ASTM D2709 for water and sediment in middle distillate fuels by centrifuge
4. Summary of Test Method
4.1 A 100-mL sample of the undiluted fuel is centrifuged at a relative centrifugal force of 800 for 10 min. at 21 to 32°C (70 to 90°F) in a centrifuge tube readable to 0.005 mL and measurable to 0.01 mL. After centrifugation, the volume of water and sediment which has settled into the tip of the centrifuge tube is read to the nearest 0.005 mL and reported as the volumetric percent water and sediment by centrifuge.
5. Significance and Use
5.1 This test method is used as an indication of water and sediment in middle distillate fuels such as Grades Nos. 1 and 2 fuel oil, (Specification D396) Nos. 1-D and 2-D diesel fuel, (Specification D975) and Nos. 0-GT, 1-GT, and 2-GT gas turbine fuels (Specification D2880).
5.2 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.
