ASTM D4304-17

1.1 This specification covers mineral and synthetic (API group I, II, III, or IV) oils used in steam and gas turbine lubrication systems where the performance requirements demand highly refined mineral or synthetic base oils compounded with rust and oxidation inhibitors plus selected additives as needed to control foam, wear, demulsibility, and so forth. This standard may also be applied to “combined cycle” turbine systems, where a single lubricant circulating system is used to supply oil to a steam and gas turbine configured in tandem either on a single or separate shaft for enhanced energy efficiency.