This Gulf standard is concerned with the mineral oils used in steam or gas turbine lubrication systems where the performance requirements demand a highly refined mineral base oil compounded with rust and oxidation inhibitor plus selected additives as needed to control foam, wear, demulsibility, etc. 1.2 This standard is intended to define the properties of mineral oil-based turbine lubricating oils that are functionally interchangeable with existing oils of this type, and are compatible with most existing machinery components and, with appropriate field maintenance, will maintain their functional characteristics. 1.3 This standard is intended to define only new lubricating oils before they are installed in the machinery.