MIL-PRF-6083 Hydraulic Fluid, Petroleum Base, For Preservation And OperationThis specification describes the characteristics and provides the requirements for one grade of petroleum base hydraulic fluid for use in the -54??C to +135??C temperature range \(see 6.1\). This fluid is rust inhibited and used both as a preservative for hydraulic systems and components as well as being an operational fluid. This hydraulic fluid will not be used for aircraft systems, aircraft ground support equipment, or the preservation of aircraft components. The hydraulic fluid is identified by Military Symbol OHT and NATO Symbol C-635.

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MIL-PRF-6083G

4. VERIFICATION

4.1 Classification of inspections.

a. Qualification inspection (see 4.2).

b. Conformance inspection (see 4.3).

4.2 Qualification inspection.

4.2.1 Qualification inspection sample. Qualification samples shall consist of a one (1) gallon

container of hydraulic fluid. The qualifying activity may request samples of the basestock and additives

used in the formulation. The qualifying activity will request data as listed in TARDEC s Guide for

Qualification of Hydraulic Fluids, Greases, Solid Film Lubricants, Solvent, Preservatives, & Stabilizer

Additives.

4.2.2 Qualification Tests. Qualification sample(s) shall be subjected to all tests specified in

Section 3 and Tables I and II.

4.2.3 Retention of Qualification. The government reserves the right to re-examine the qualified

product whenever deemed necessary to determine that the product continues to meet any or all of the

specification requirements. Requalification is required every 5 years. Changes in formulation or

materials shall require requalification.

4.3 Conformance inspections. Conformance inspections shall consist of tests for all of the

requirements specified in section 3, except the following:

a. Corrosiveness and oxidation stability

b. Shear stability

c. Storage stability

Unless otherwise specified (see 6.2), the sample representative of each fifth batch shall be

subjected to tests for all of the requirements specified in section 3 except the following:

d. Shear stability

e. Storage stability

4.4 Sampling.

4.4.1 Sampling for tests (except particulate contamination). Samples for tests, except

particulate contamination, shall be taken in accordance with ASTM D4057 or D4177.

4.4.2 Sampling for determination of particle size contamination. The sample size and number of

determinations per sample for the respective containers shall be as specified in table III. Should the

particle count on any individual determination be considered excessive, two additional determinations on

another sample from the same container may be used. The container shall be thoroughly shaken for

approximately one minute immediately prior to withdrawing each 100mL portion for all determinations.

The arithmetic average of the two closer particle counts shall be considered the particle count for the

sample.