This specification covers mineral lubricating oils used in steam and gas turbine lubricating systems where the performance requirements demand a highly refined mineral base oil compounded with rust and oxidation inhibitors plus selected additives as needed to control foam, wear, demulsibility, and so forth. This specification is intended to define the properties of new mineral oil-based turbine lubricating oils that are functionally interchangeable with existing oils of this type, are compatible with most existing machinery components, and with appropriate field maintenance, will maintain their functional characteristics. The lubricating oils shall meet the functional property limits specified for each type, as follows: ISO-viscosity grade; ASTM color; specific gravity, flash point, and pour point; water content and viscosity; visual examination; total acid number; emulsion characteristics; foaming characteristics; air release; rust preventing characteristics; copper corrosion; oxidation stability; 1000-h TOST sludge and total acid number; and cleanliness at the delivery stage.

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.

1.2 This specification is intended to define the properties of mineral and synthetic oil-based turbine lubricating oils that are functionally interchangeable with existing oils of this type, are compatible with most existing machinery components, and with appropriate field maintenance, will maintain their functional characteristics.

1.3 This specification is intended to define only new lubricating oil before it is installed in the machinery.

1.4 This specification is intended to be used as a guide. It is possible that oils that do not meet this specification may perform satisfactorily in some turbines.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.