ASTM D8112-22

5.1Fluid analysis is one of the pillars in determining fluid and equipment conditions. The results of fluid analysis are used for planning corrective maintenance activities, if required.

5.2The objective of a proper fluid sampling process is to obtain a representative fluid sample from critical location(s) that can provide information on both the equipment and the condition of the lubricant or hydraulic fluid.

5.3The additional objective is to reduce the probability of outside contamination of the system and the fluid sample during the sampling process.

5.4The intent of this guide is to help users in obtaining representative and repeatable fluid samples in a safe manner while preventing system and fluid sample contamination.

1.1This guide is applicable for collecting representative fluid samples for the effective condition monitoring of steam and gas turbine lubrication and generator cooling gas sealing systems in the power generation industry. In addition, this guide is also applicable for collecting representative samples from power generation auxiliary equipment including hydraulic systems.

1.2The fluid may be used for lubrication of turbine-generator bearings and gears, for sealing generator cooling gas as well as a hydraulic fluid for the control system. The fluid is typically supplied by dedicated pumps to different points in the system from a common or separate reservoirs. Some large steam turbine lubrication systems may also have a separate high pressure pump to allow generation of a hydrostatic fluid film for the most heavily loaded bearings prior to rotation. For some components, the lubricating fluid may be provided in the form of splashing formed by the system components moving through fluid surfaces at atmospheric pressure.

1.3Turbine lubrication and hydraulic systems are primarily lubricated with petroleum based fluids but occasionally also use synthetic fluids.

1.4For large lubrication and hydraulic turbine systems, it may be beneficial to extract multiple samples from different locations for determining the condition of a specific component.

1.5The values stated in SI units are regarded as standard.

1.6This 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.

1.7This 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.