Significance and Use,The CFPP of a fuel is suitable for estimating the lowest temperature at which a fuel will give trouble-free flow in certain fuel systems.The difference in results obtained from the samples as received and after heat treatment at 45 degrees Celsius for 30 minutes, can be used to investigate complaints of unsatisfactory performance under low temperature conditions.
Significance and Use, The heat of combustion is a measure of the energy available from a fuel. A knowledge of this value is essential when considering the thermal efficiency of equipment for producing either power or heat. The mass heat of combustion per unit mass of fuel, is a critical property of fuels intended for use in weight limited crafts such as airplanes, surface effect vehicles, and hydrofoils. The range of such craft between refueling is a direct function of the heat of combustion and density of the fuel.
Significance and Use, Crude petroleum contains sulfur compounds, most of which are removed during refining. However, of the sulfur compounds remaining in the petroleum product, some can have a corroding action on various metals and this corrosion is not necessarily related directly to the total sulfur content. The effect can vary according to the chemical types of sulfur compounds present. The copper strip corrosion test is designed to assess the relative degree of corrosion of a petroleum product.
A polished steel spindle is immersed into 100 milliliters of fuel maintained at 100 degrees feirignheight. The fuel is continually stirred during the entire test period. Upon immersion for 30 minutes, 30 milliliters of distilled water are added to the fuel. After remaining in the fuel for an additional 3 1/2 hours, the spindle is removed and the surface is rated for percent of corrosion. The ratings go from A which is 0% corrosion down to E. B is 5-25% which is also considered a pass. There are also B++ and B+ ratings.
Significance and Use, Diesel fuel injection equipment has some reliance on lubricating properties of the diesel fuel. Shortened life of engine components, such as diesel fuel injection pumps and injectors, has sometimes been ascribed to a lack of lubricity in a diesel fuel. The trend of HFRR test results to diesel injection system pump component distress due to wear has been demonstrated in pump rig tests for some fuel/hardware combinations, where boundary lubrications is believed to be a factor in the operation of the component. The wear scar generated in the HFRR test is sensitive to contamination of the fluids and test materials and the temperature of the test. Lubricity evaluations are also sensitive to trace contaminations acquired during test fuel sampling and storage. The HFRR may be used to evaluate the relative effectiveness of diesel fuels for preventing wear under the prescribed test conditions.