1. Scope

1.1 This specification covers water insoluble and oil soluble polyalkylene glycol-based (PAG) lubricants used in steam and gas turbine lubrication systems. This specification may also be applied to combined cycle turbine systems in which 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 water insoluble or oil soluble polyalkylene glycol-based turbine lubricating oils that are functionally interchangeable with existing oils of this type, 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 fluids before it is installed in the machinery. 1.4 This specification is intended to be used as a guide. It is possible that other water insoluble and oil soluble polyalkylene glycol-based turbine lubricants that do not meet this specification may perform satisfactorily in some turbines. 1.5 This specification does not include API Group - or non-PAG-based API Group oils. For mineral oil and synthetic (API group , , , or ) fluids used to lubricate steam or gas turbines, the user is referred to the current version of D4304. ISO 8068, DIN 51515-1, or DIN 51515-2 may also be of useful reference. This specification does not include API Group l-V oils. For polyol ester fluids used to lubricate land-based gas turbines, the user is referred to the current version of MIL-PRF-23699 for fluid performance requirements. For phosphate ester fluids used as turbine lubricants or steam turbine electro-hydraulic control (EHC) fluids, the user is referred to the current version of Specification D4293 for fluid performance requirements. 1.6 Units--The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard. 1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

Keywords

combined cycle polyalkylene glycol turbine lubricant; polyalkylene glycol, polyglycols; PAG; water insoluble PAG; oil soluble PAG; polyalkylene glycol gas turbine lubricants; polyalkylene glycol gas turbine lubricants; turbine lubrication systems; polypropylene glycol; polybutylene glycol; co-polymers of propylene oxide and butylene oxide; alkoxylate; long-chain alcohol

Rationale

Polyalkylene glycol (PAG) turbine lubricants are currently being used in gas and steam turbine lubricating systems. PAG base stocks are different from mineral oil base stocks in chemical composition as they contain the element oxygen which mineral oils do not. The properties of the fluids then are not identical and may differ slightly or more significantly. Those differences may dictate different specification test limit parameters or different tests or both than those stated currently in ASTM D4304. End users responsible for the selection of a turbine oil for a steam or gas turbine lubricating system need to have a standard specification for PAG turbine lubricants providing property and performance requirements for reference as they currently do for mineral and other synthetic turbine oils.

The title and scope are in draft form and are under development within this ASTM Committee.