ASTM D2428-92

1.1 This test method covers a procedure for system evaluation of aerospace hydraulic fluids. The test method recommends control of test variables, a typical test system geometry, data to be obtained, and procedures which will assure a uniform approach to fluid screening and evaluation. Recommendations concerning specific hardware and rigid techniques have been avoided where possible to allow the test method to be used as the state-of-the-art advances.

1.2 Each agency using the test method can simulate a specific system, thus fluids can be qualified for use in applications having unique hardware and design concepts. This approach provides the test flexibility needed to meet the rapid changes in fluid requirements and also provide valuable comparative data for both users and developers of hydraulic fluids.

1.3 Since the test system was purposely generalized, it is important that the specified data be obtained in order that fluid flow dynamics can be defined. Such factors as shear rate, mass flow rate, temperature gradients, etc., must be defined for valid comparisons.

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

1.5 The values stated in metric units are to be regarded as the standard. The values given in parentheses are for information only.