1.1 This practice covers the compatibility of mixtures of hydraulic fluids as defined by Specifications D6158, DIN 51524, ISO 11158, and ISO 15380.
1.2 This practice can be used to evaluate new (unused) lubricant compatibility or the effects of combining new (replacement) lubricant with in-service (original) lubricant in the system.
1.3 To evaluate primary compatibility using this method, the replacement fluid must pass the ISO 13357-1 Stage II filterability test. The original fluid is not required to pass ISO 13357-1 filterability test, Stage I or II.
1.4 Primary testing is conducted on fluid mixtures in 2:98, 10:90, and 50:50 ratios using the ISO 13357-1 Filterability Test, Stage II.
1.5 Secondary testing is suggested when circumstances indicate the need for additional testing.
1.6 This practice does not evaluate the wear prevention characteristics, load carrying capacity, or the mechanical shear stability of lubricant mixtures while in service. If anti-wear (AW), extreme pressure (EP), or shear stability are to be evaluated, further testing of these parameters may be required.
1.7 This practice does not purport to cover all test methods that could be employed.
1.8 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.9 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.
1.10 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 D7752-18 Referenced Document
ASTM D130 Standard Test Method for Detection of Copper Corrosion from Petroleum Products by the Copper Strip Tarnish Test
ASTM D1401 Standard Test Method for Water Separability of Petroleum Oils and Synthetic Fluids
ASTM D2270 Standard Practice for Calculating Viscosity Index From Kinematic Viscosity at 40 and 100176C
ASTM D3427 Standard Test Method for Air Release Properties of Petroleum Oils
ASTM D445 Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (the Calculation of Dynamic Viscosity)
ASTM D6158 Standard Specification for Mineral Hydraulic Oils
ASTM D664 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
ASTM D665 Standard Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water
ASTM D7042 Standard Test Method for Dynamic Viscosity and Density of Liquids by Stabinger Viscometer (and the Calculation of Kinematic Viscosity)*, 2021-11-01 Update
ASTM D892 Standard Test Method for Foaming Characteristics of Lubricating Oils
ASTM D974 Standard Test Method for Acid and Base Number by Color-Indicator Titration
ASTM D7752-18 history
2018ASTM D7752-18 Standard Practice for Evaluating Compatibility of Mixtures of Hydraulic Fluids
2011ASTM D7752-11 Standard Practice for Evaluating Compatibility of Mixtures of Hydraulic Fluids