ASTM International Standard Specification for Mineral and Synthetic Lubricating Oil Used in Steam or Gas Turbines ASTM D4304-22

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.