1.1 This practice covers all types and grades of hydraulic fluids.
1.2 This practice is applicable to both laboratory and field evaluations.
1.3 This practice provides guidelines for conducting hydraulic fluid evaluations. It does not prescribe a specific efficiency test methodology.
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.
ASTM D7721-22 Referenced Document
ASTM D4174 Standard Practice for Cleaning, Flushing, and Purification of Petroleum Fluid Hydraulic Systems
ASTM D4175 Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants*, 2023-07-01 Update
ISO 4391 Hydraulic fluid power; Pumps, motors and integral transmissions; Parameter definitions and letter symbols
ISO 4409 Hydraulic fluid power — Positive-displacement pumps, motors and integral transmissions — Methods of testing and presenting basic steady state performance
ISO 5598 Fluid power systems and components — Vocabulary
ISO 8426 Hydraulic fluid power - Positive displacement pumps and motors - Determination of derived capacity
ASTM D7721-22 history
2022ASTM D7721-22 Standard Practice for Determining the Effect of Fluid Selection on Hydraulic System or Component Efficiency
2017ASTM D7721-17 Standard Practice for Determining the Effect of Fluid Selection on Hydraulic System or Component Efficiency
2011ASTM D7721-11 Standard Practice for Determining the Effect of Fluid Selection on Hydraulic System or Component Efficiency