ASTM D2880 Standard Specification for Gas Turbine Fuel Oils
4. General Requirements
4.1 The fuels herein specified 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.
4.2 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.
5. Detailed Requirements
5.1 The various grades of gas turbine fuel oil shall conform to the limiting requirements shown in Table 1. As noted in the supplementary footnotes to Table 1, the requirements for Grade Nos. 1-GT and 2-GT conform in most respects to corresponding Grade Nos. 1 and 2 fuels in Specification D396, and to Grade Nos. 1-D and 2-D in Specification D975. The viscosity range of Grade Nos. 3-GT and 4-GT fuel brackets the Grade Nos. 4, 5, and 6 of Specification D396 and Grade No. 4-D of Specification D975. It is the intent that fuels meeting Specification D396 and D975 requirements may also be supplied under these specifications provided they meet the requirements listed in Table 1.
5.2 Modifications of limiting requirements and the inclusion of fuel additives to meet special operating conditions may be agreed upon between the interested parties.
5.3 The properties listed in this specification are those of greatest significance in obtaining acceptable performance of the turbine. However, trace metals, even in fractional parts per million, are detrimental to gas turbine service life. Information on the maximum concentration of critical metallic elements in the fuel as it enters the turbine combustor(s) is provided in Appendix X2. Distillate fuels are usually of satisfactory purity as refined, but suppliers rarely have control over possible contamination by trace metals in distribution and storage. The limits in Appendix X2, although required as the fuel enters the combustor(s), do not apply to the fuel as delivered unless mutually agreed upon by the interested parties. Fuels may, therefore, require on-site clean-up, quality control procedures, special handling, or other arrangements.
