Standard Guide for Management of In-Service Phosphate Ester-based Fluids for Steam Turbine Electro-Hydraulic Control (EHC) Systems

1.1 This guide provides recommendations to achieve safe and reliable operation of EHC systems, recommended levels for required corrective action, and suggested management practices.

1.2 The recommended set of physical and chemical properties of triaryl phosphate esters and their limits have been selected based on past operating experience with various fluids (primarily xylylated and butylated triaryl phosphate esters) used in different EHC system designs under different operating and environmental conditions.

1.3 This guide is not intended to replace Original Equipment Manufacturer (OEM) specifications but rather support users experiencing operating problems by recommending limits based on existing knowledge of triaryl phosphate ester degradation mechanisms. This guide should be used outside the warranty period or in cases where no OEM standard exists or is available.

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

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 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.