Abstract
This specification covers the selection of fuels for gas turbines, excepting gas turbines used in aircraft, for the guidance of interested parties such as turbine manufacturers and the suppliers and purchasers of fuel oils. The specification sets forth the properties of fuels at the time and place of custody transfer to the user. The fuels shall be homogeneous mixtures of hydrocarbon oils free of inorganic acid, and free of excessive amounts of solid or fibrous foreign matter likely to make frequent cleaning of suitable strainers necessary. All grades containing residual components shall remain homogeneous in normal storage and not separated by gravity into light and heavy oil components outside the viscosity limits for the grade. The following test methods shall be performed to determine certain properties: flash point test, pour point test, water and sediment test, carbon residue test, ash test, distillation test, viscosity test, density test, and sulfur test.
Scope
1.1 This specification covers the grades of fuels for gas turbines, excepting gas turbines used in aircraft, for the guidance of interested parties such as turbine manufacturers and the suppliers and purchasers of fuel oils. These grades are described as follows:
1.1.1 Grades No. 0-GT S5000, No. 0-GT S500, and No. 0-GT S15 includes naphtha, Jet B, and other light hydrocarbon liquids that characteristically have low flash point and low viscosity as compared with kerosine and fuel oils.
1.1.2 Grades No. 1-GT S5000, No. 1-GT S500, and No. 1-GT S15 are a light distillate fuel oil suitable for use in nearly all gas turbines.
1.1.3 Grades No. 2-GT S5000, No. 2-GT S500, and No. 2-GT S15, which is a heavier distillate than Grade No. 1-GT, can be used by gas turbines not requiring the clean burning characteristics of Grade No. 1-GT. Fuel heating equipment may be required by the gas turbine depending on the fuel system design or ambient temperature conditions, or both.
1.1.4 Grade No. 3-GT may be a heavier distillate than Grade No. 2-GT, a residual fuel oil that meets the low ash requirements, or a blend of distillate with a residual fuel oil. Fuel heating will be required by the gas turbine in almost every installation.
1.1.5 Grade No. 4-GT includes most residuals and some topped crudes. Because of the wide variation and lack of control of properties, the gas turbine manufacturer should be consulted with regard to acceptable limits on properties.
1.2 Three appendixes are provided for informational purposes only and do not constitute a requirement of this specification unless mutually agreed upon between the interested parties.
1.2.1 Appendix X1 describes the five grades of gas turbine fuels covered by this specification. Further, it states the significance of various test methods used in inspecting the fuels.
1.2.2 Appendix X2 discusses the sources of fuel contaminants and notes the significance of such contaminants in the operation of gas turbines and gas turbine fuel systems. The particular significance of trace metals in gas turbine fuels is noted. Upper limits of trace metals are recommended for the various grades of gas turbine fuels, but these recommended limits do not constitute a requirement of the specification unless mutually agreed upon by the interested parties. Limitations due to the use of used or recycled oil are also noted.
Note 1: The gas turbine operator should consult Practice D4418 for methods of ensuring fuels of adequate cleanliness and for guidance on long-term storage of distillate fuels and on liquids from non-petroleum sources as gas turbine.
Note 2: The generation and dissipation of static electricity can create problems in the handling of distillate gas turbine fuel oils. For more information on the subject, see Guide D4865.
1.3 This specification, unless otherwise provided by agreement between the purchaser and the supplier, prescribes the required properties of gas turbine fuel oils at the time and place of delivery.
1.4 Nothing in this specification shall preclude observance of federal, state, or local regulations which may be more restrictive.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
